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We demonstrate the first successful attempt to partially substitute Cu into the Mn3AgN-antiperovskite system to form Mn3Ag(1-x)Cu(x)N thin films with an ultra-low temperature coefficient of resistance (TCR) for fabrication of ultra-precise passive components. Films were grown by reactive magnetron sputtering on alumina and glass substrates and were found to be amorphous in nature with highly negative TCR of -233 to -351 ppm/°C in their as-grown state. Increasing Cu alloying from x=0 to 1, resulted in increased sheet resistance, a negative shift of TCR and a change of grain morphology from spherical to elongated. Post-deposition heat treatment at 300-375 °C, resulted in a positive shift of TCR and an ultra-low TCR of -4.66 ppm/°C for films with x=0.6. The heat treatment induces grain growth, surface roughness and the formation of a manganese oxide upper surface layer up until temperatures of 350 °C, after which surface oxidation begins to dominate. The growth rate of the surface layer is controlled by the Cu concentration and heat treatment temperature, which both play a central role in the development of these novel ultra-low TCR Mn3Ag(1-x)Cu(x)N thin film structures.

Pt/Co/Hf multilayers were prepared by magnetron sputtering, and the magnetic anisotropy was effectively regulated by Hf thickness and heat treatment in Pt/Co/Hf films. The interface microstructures were characterized. The influence of the interface microstructure on magnetic properties was studied. The results show that the magnetic anisotropy in Pt/Co/Hf films is closely related to the interface microstructure, which is influenced by Hf thickness and the heat treatment temperature. Microstructure analysis shows that after the Pt(3)/Co(1.5)/Hf(1) film is heat-treated, the CoOx content increases, more CoPt(111) forms, the interface is smoother and sharper, and the roughness of the Co/Hf interface decreases. Several factors work together to cause the magnetic anisotropy of the sample to change from in-plane magnetic anisotropy (IMA)to perpendicular magnetic anisotropy (PMA).

Beta-gallium oxide (β-Ga2O3) thin films were prepared on a MgO (100) substrate under different oxygen flow ratios via magnetron sputtering. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and UV–visible near-infrared (UV–vis–NIR) analyses were conducted to study how the oxygen flow ratio affected the crystalline quality and the surface topography of the films. Microstructure analysis revealed a clear out-of-plane orientation of β-Ga2O3 (100) || MgO (100). The film deposited under an oxygen flow ratio of 1% presented the optimal single-crystalline structure, while excess oxygen was confirmed to negatively impact the crystallization characteristics of the films. SEM measurements indicated that the increase in the oxygen flow ratio reduced the grain size and RMS roughness. The average transmittance of the β-Ga2O3 films in the visible range exceeded 83%, with a broad luminescence band exhibited at approximately 485 nm in the photoluminescence (PL) spectra.

Using wide-band (0.5-6.5 eV) spectroscopic ellipsometry we study ultrathin [Bi(0.6-2.5 nm)-FeNi(0.8,1.2 nm)]N multilayer films grown by rf sputtering deposition, where the FeNi layer has a nanoisland structure and its morphology and magnetic properties change with decreasing the nominal layer thickness. From the multilayer model simulations of the ellipsometric angles, Psi(omega) and Delta(omega), the complex (pseudo)dielectric function spectra of the Bi layer were extracted. The obtained results demonstrate that the Bi layer can possess the surface metallic conductivity, which is strongly affected by the morphology and magnetic properties of the nanoisland FeNi layer in the GMR-type Bi-FeNi multilayer structures., 6 pages, 4 figures

International audience; Quaternary germanium-antimony-selenium-tellurium (Ge-Sb-Se-Te) thin films deposited from Ge19.4Sb16.7Se63.9-xTex (x = 5, 10, 15, and 20) glass-ceramics targets by radio frequency magnetron sputtering were studied using laser ablation quadrupole ion trap time of flight mass spectrometry. Binary, ternary, and quaternary GeaSbbSecTed clusters were formed and their stoichiometry was determined. By comparison of the clusters obtained from quaternary Ge-Sb-Se-Te thin films and those from ternary Ge-Sb-Te materials, we found that Ge-Te species are not detected from the quaternary system. Furthermore, Ge-Se and Se-Te species are missing in mass spectra generated from Ge-Sb-Se-Te thin films. From the Ge-Sb-Se-Te thin films, 16 clusters were detected while ternary Ge-Sb-Se glasses yielded 26 species. This might be considered as a signal of higher stability of Ge-Sb-Se-Te thin films which is increasing with a higher content of Te. The missing (Se-2(+), GeaSb+ (a = 1-4), and GeSec+ (c = 1, 2)) and new (Ge+ and SbbTe+ (b = 1-3)) clusters may indicate that some of the structural features of the films (Ge2Se6/2 and Se2Sb-SbSe2) were replaced by (GeSe4-x,Te-x and SbSe3-xTex) ones. In addition, when comparing the stoichiometry of clusters formed from Ge-Sb-Se-Te thin films with those from the mixtures of the elements, only Sb-3(+) and SbSe+ were observed in both cases. The knowledge gained concerning clusters stoichiometry contributes to the elucidation of the processes proceeding during plasma formation used for the chalcogenide thin films deposition.

In this work, vanadium pentoxide (V2O5) thin films were prepared using rf magnetron sputtering on silicon wafer and glass substrates from V2O5 target at 200 °C substrate temperature, followed by annealing at 400 and 500 °C in air for 2 h. The prepared thin films were examined by X-ray diffraction (XRD), forier transform infra-red spectroscopy (FTIR), UV-visible absorbance, and direct current coductivity to study the effects of annealing temperature on their structural and optical properties. The XRD analysis exhibited that the annealing promoted the highly crystallized V2O5 phase that is highly orientated along the c direction. The crystalline size increased from 22.5 nm to 35.4 nm with increasing the annealing temperature to 500 °C. The FTIR spectroscopy showed the enhancement of the characteristics band for the V2O5 with increasing annealing temperature to 500 °C. The optical study showed that the energy gap for the sample deposited on glass slides decreased from 2.85 eV, for as deposited sample, to 2.6 eV upon annealing the sample to 500 °C. There was a linear dependence between sensitivity and relative humidity (RH) at the range from 25% to 70%, while the behavior was exponential at high RH range.

Thick Cu-doped Sb2Te3 films were deposited on flexible substrate by DC magnetron sputtering from a mosaic Cu–Sb2Te3 target. The Cu-doped Sb2Te3 films were vacuum annealed to improve their thermoelectric properties. Density functional theory was used to clarify the internal mechanism of the Cu doped into the Sb2Te3 system. The results showed that Cu substitution on a Sb site induced electronic states or impurity peaks of Sb2Te3 at a valence band maximum. The carrier concentration of the Cu-doped Sb2Te3 films increased as the Cu-doped concentration increased. However, the crystallite size and Seebeck coefficient of the Cu-doped Sb2Te3 films decreased as the Cu-doped concentration increased. Post-annealing treatment improved the microstructure and thermoelectric properties of the Cu-doped Sb2Te3 films. The maximum electrical conductivity and power factor values of 754.20 S/cm at 50 °C and 1.56 10−3 W/mK2 at 100 °C were obtained in the annealed film with a Cu-doped concentration of 3 at%.

The fabrication of high-quality epitaxial BiFeO3 (BFO) thin films is critical for their integrated device applications. This work demonstrates a modification of two cooling atmospheres, i.e., pure O2 and mixed Ar/O2, on the crystalline phase and electrical properties of BFO thin films prepared by radio-frequency magnetron sputtering. A good epitaxial growth of BFO thin films with a coexistence of dominant rhombohedral (R) and partial tetragonal (T) phases is identified by XRD analyses. Compared to an extremely small amount of (100)-oriented T phase detected in the BFO thin film cooled in mixed Ar/O2, an increased amount of T phase with (001) orientation is observed in the film cooled in pure O2. In addition, compared with the poor electrical properties, including leakage, dielectric behavior, and ferroelectric polarization, of the BFO film cooled in mixed Ar/O2, the film cooled in pure O2 exhibits the improved electrical properties, e.g., a low leakage current (J

Hybrid Nb(20)/Cu(5)/Py(2), Nb(20)/Cu(5)/Co(40) and Nb(20)/Cu(d $$_{Cu}$$ )/Py(2)/Cu(5)/Co(40) heterostructures (values in nanometers and d $$_{Cu}$$ = 0, 2.5 and 5.0) were fabricated using a confocal DC magnetron sputtering setup. Performing magnetotransport measurements and using the anisotropic Ginzburg–Landau approach, the stray field values in zero-applied field ( $$B_\mathrm{0Co}$$ , $$B_\mathrm{0Py}$$ and $$B_\mathrm{0Py+Co}$$ ) were estimated as being $$- 9~$$ mT ( $$+ 31~$$ mT) for the hybrid Nb/Cu/Co (Nb/Cu/Py) trilayers and $$+ 36~$$ mT for the hybrid ordinary Nb/Cu(5)/Py/Cu/Co spin-valve heterostructure. The effective fields acting on the superconducting layer in the hybrid non-ordinary Nb/Cu/Py and Nb/Cu/Co spin-valve heterostructures and its dependence with the applied magnetic field were also quantified, showing that the stray fields of thin ferromagnetic layers are the same order of magnetide but with different strengths. For an applied field of 1 T, the spin-valve effect values of $$-~230~$$ mK ( $$+~300~$$ mK), previously found for the hybrid Nb/Cu/Co (Nb/Cu/Py) trilayers and $$+~140$$ mK for the Nb/Cu(5)/Py/Cu/Co heterostructure, had their physical origin better discussed and demonstrated. The 2-nm-thick ferromagnetic Py layer strongly contributes to the effective fields, and the low spin-valve effect of $$+~140$$ mK for the ordinary Nb/Cu(5)/Py/Cu/Co spin-valve heterostructure would be a consequence of two contributions of opposite signs governed by the Py and Co layers and also due to the proximity effect contribution.

In this work, Zr–B–N coatings were obtained by the method of high-power impulse magnetron sputtering (HIPIMS) in Ar, Ar + 15%N2, and N2 gaseous media using a ZrB2 SHS target. Sputtering was carried out at the following parameters: medium power of 1 kW, peak power of 70 kW, peak current of 130 A, frequency of 100 Hz, pulse duration of 200 μs. The working pressure in the vacuum chamber was 0.1–0.2 Pa, the distance between the substrate and the target was 80 mm, and the coating deposition time was 40 minutes. Glass, silicon, and high-speed steel were used as substrates. For comparison with the HIPIMS method, the coatings were also applied by direct current magnetron sputtering (DCMS) at an average power of 1 kW. The composition and structure of the coatings were studied by scanning electron microscopy (SEM), glow discharge optical emission spectroscopy (GDOES), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analysis. The mechanical, tribological and optical properties of Zr–B–N coatings, as well as resistance to impact dynamic loading, were studied. All coatings were characterized by a dense structure and the absence of columnar grains. With the help of spectroscopic structural studies of coatings, it was revealed that during deposition in a reaction medium, the BN phase is formed, which has a significant effect on the microstructure and characteristics of the coatings. An increase in the nitrogen concentration in the gas mixture during the deposition of Zr–B–N coatings led to an increase in the optical transmittance of the coatings up to 97 %, resistance to cyclic impact dynamic loads by 40 %, and a decrease starting value of friction coefficient by 60 %. The non-reactive coating had a maximum hardness of 19 GPa and an elastic modulus of 221 GPa.

Using the reactive DC magnetron sputtering of two separate single-element Ti and Pb targets, a TiN–Pb composite coating was deposited onto a substrate made of VT6 titanium alloy. The studies are carried out on currents on the Pb cathode of 0.2 and 0.1 A and two fixed values of the argon flow rate of 6.0 or 8.5 cm3/min, as well as the flow rate of nitrogen supplied to the chamber varying from experiment to experiment. The composition of the coatings is determined by energy dispersive analysis. It is shown that the amount of lead in the coatings ranges from 0.5 to 16%, depending on the current on the Pb cathode and reactive gas consumption N. The microhardness and wear of the coatings are determined for each deposition mode. Depending on the ratio of argon and nitrogen fluxes, the thickness of the coatings varies from 1.9 to 5.2 μm. The effect of the deposition parameters of magnetron TiN–Pb coatings on the structure and phase composition is investigated by the X-ray diffraction method. It is shown that, at a current value of 0.2 on the Pb cathode, the coating consists of Pb and PbO and, at a current of 0.1 A, it consists of TiN, Pb, and PbO, while an increase in the ratio of argon and nitrogen fluxes leads to an increase in the fraction of TiN, the intensity of surface saturation, titanium substrate with nitrogen, microhardness, and wear resistance. Under all deposition conditions, the TiN coating is characterized by a typical texture (111), the intensity of which varies nonmonotonically.

Simple Wheatstone bridge-giant magnetoresistance (GMR) sensors with one and two spin-valve (SV) thin films were developed for detecting magnetic nanoparticles (MNPs). SV thin films with a Ta(2 nm)/Ir20Mn80(10 nm)/Co90Fe10(3 nm)/Cu(2.2 nm)/(Co90Fe10)92B8(10 nm)/Ta(5 nm) structure were fabricated using RF magnetron sputtering on Si/SiO2 substrates. Inverse spinel-structured Fe3O4 and Fe3O4/polyethylene glycol (PEG) MNPs were synthesized by coprecipitation methods. To investigate the GMR sensor response, MNPs-ethanol (10 μL) solutions were dropped on the surface of the thin films. The following changes in Fe3O4 were observed after coating with PEG: the size of the nanoparticles increased from 11 to 13 nm, and the saturation magnetization of Fe3O4 decreased from 77.0 to 49.6 emu/g, which can be attributed to the surface modifications by PEG polymer; furthermore, the coercivity increased from 51.2 to 61.5 Oe owing to the existence of the antiferromagnetic phase α-Fe2O3. The output voltage of the GMR sensor with one and two SV thin film elements for Fe3O4 changed by 2.2 and 5.5 mV, respectively, and the output voltage decreased to 1.4 and 1.5 mV, respectively, in the case of Fe3O4/PEG. The decrease in the output voltage was caused by the decrease in the saturation magnetization of Fe3O4 after coating with PEG.

DC reactive magnetron sputtering of two separate single-element Ti and Pb targets was used to deposit a TiN–Pb composite coating onto a substrate made of the VT6 titanium alloy. The studies were carried out at Pb cathode currents of 0.2 and 0.1 A and two fixed argon flow rate values of 6.0 or 8.5 cm3/min, and the flow rate of nitrogen supplied to the chamber varying from experiment to experiment. The composition of coatings was determined by energy dispersive analysis. It was shown that the amount of lead in the coatings ranged from 0.5 to 16 wt.% depending on the Pb cathode current and reactive nitrogen consumption. Coating microhardness and wear were determined for each deposition mode. It was found that coating thicknesses varied from 1.9 to 5.2 μm depending on the ratio of argon and nitrogen fluxes. The effect of TiN–Pb magnetron coating deposition parameters on the structure and phase composition was investigated by X-ray diffraction method. It was shown that the coating consists of Pb and PbO at the Pb cathode current of 0.2 A, and of TiN, Pb, and PbO at the current of 0.1 A, while an increase in the ratio of argon and nitrogen fluxes leads to an increase in the fraction of TiN, the intensity of titanium substrate surface saturation with nitrogen, as well as microhardness and wear resistance. Under all deposition conditions the TiN coating features by a typical texture (111), the intensity of which varies nonmonotonically.

We investigate the structural properties of Fe1−xNix/Cu/Fe1−xNix ( x=0.5, non-Invar and x=0.36, Invar) trilayers deposited on Si(100) at room temperature using the dc magnetron sputtering technique...

Nb3Sn is considered as a potential candidate for superconducting radiofrequency cavities for particle acceleration due to its higher transition temperature of 18.3 K and higher superheating field of 400 mT. Nb3Sn films can be grown inside the surface of a Nb cavity by sequentially sputtering multiple layers of Nb and Sn thin films followed by annealing at 950 °C for 3 h. We report on the properties of Nb3Sn films grown on Nb substrates by magnetron sputtering. The films’ crystal structure, surface morphology, and composition were characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The films had a polycrystalline Nb3Sn structure with a fine-grain surface and an atomic Sn composition of ∼23%. The RF surface resistance of the films was measured for different temperatures at 7.4 GHz to understand the feasibility of this method for the SRF application. The RF surface resistance of the films was 5 mΩ at 12 K, which is about 2 orders of magnitude higher than 60 μΩ previously measured in Nb3Sn films grown by Sn vapor diffusion. The sputtered film had a superconducting transition at 17.2 K, which is also lower than 17.9 K observed in Nb3Sn film prepared by vapor diffusion.

This study presents the results of theoretical and experimental investigations of zinc oxide (ZnO) and aluminum-doped zinc oxide (AZO) thin films, prepared by RF magnetron sputtering. The structural, optical and morphological properties were examined, and the results show that the AZO thin films exhibit a higher optical transmittance compared to intrinsic ZnO films of the same thickness. Also, the XRD data show a change from vertical growth along (002) crystallographic plane to lateral growth along (103) crystallographic plane with Al doping. The experimental optical parameters of the prepared ZnO and AZO films were determined and confirmed by the density functional theory (DFT), while the corresponding electronic structures have been investigated using DFT calculations with modified Becke–Johnson exchange potential (mBJ) and generalized gradient approximation (GGA). From the results, it is shown that the optical band gap is blueshifting from 3.13 eV to 3.45 eV with Al doping due to the Burstein–Moss effect.

We have studied the charge-injection characteristics and electrochemical impedance of sputtered ruthenium oxide (RuO(x)) films as electrode coatings for neural stimulation and recording electrodes. RuO(x) films were deposited by reactive DC magnetron sputtering, using a combination of water vapor and oxygen gas as reactive plasma constituents. The cathodal charge storage capacity of planar RuO(x) electrodes was found to be 54.6 ± 9.5 mC/cm(2) (mean ± SD, n = 12), and the charge-injection capacity in a 0.2-ms cathodal current pulse was found to be 7.1 ± 0.3 mC/cm(2) (mean ± SD, n = 15) at 0.6 V positive bias versus Ag|AgCl, in phosphate buffer saline at room temperature for ~250 nm thick films. In general, the RuO(x) films exhibited high charge-injection capacities, with or without a positive interpulse bias, comparable to sputtered iridium oxide (SIROF) coatings. The charge-injection capacity increased monotonically with film thickness from 120 to 630 nm, and reached 11.30 ± 0.34 mC/cm(2) (mean ± SD, n = 5) at 0.6 V bias versus Ag|AgCl at 630 nm film thickness. In addition, RuO(x) films showed minimal changes in electrochemical characteristics over 1.5 billion cycles of constant current pulsing at a charge density of 408 μC/cm(2) (8 nC/phase, 200 μs pulse width). The findings of low-impedance, high charge-injection capacity, and long-term pulsing stability suggest the suitability of RuO(x) as a comparatively inexpensive and favorable choice of electrode material for neural stimulation and recording.

© 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.In this work, we reported the effect of different metal contacts on performance of metal–oxide–semiconductor (MOS)-structured Schottky diodes formed with the vanadium pentoxide thin film (V2O5) interfacial layer. V2O5 thin films were deposited by radio frequency (RF) magnetron sputtering on n-type silicon (n-Si) and Corning glass (CG) substrates at room temperature. Then, the obtained films were annealed at 300 °C and 500 °C. The effects of annealing temperature on physical properties of the films were investigated by X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, atomic force microscopy, UV–Vis spectroscopy, and photoluminescence. The MOS-structured Al/V2O5/n-Si, Ti/V2O5/n-Si and Au/V2O5/n-Si Schottky barrier diodes (SBDs) performance was analyzed with I–V measurements at room temperature. The Schottky diodes were compared with each other according to three methods (Classic, Norde and Cheung). The experimental results indicated that the Schottky diode produced with Al contact had better performance than the others.

Optical emission spectroscopy (OES) has been used as an in-situ method to monitor the film deposition carried out using a combination of two plasma-assisted techniques; pulsed laser deposition (PLD) and magnetron sputtering (MS). In this work, the plasmas produced during the PLD ablation of a gold target in an argon atmosphere and its simultaneous use with MS of ZnO were characterized by OES. Neutral atoms of Au, Ar, and Zn and ions of Au were identified, and the temporal and spatial evolution of their emission lines was studied along the axis of the PLD plasma expansion. During the PLD of Au an increment in the emission intensity of neutral Au near the substrates, as a function of the laser pulse fluence, demonstrated resputtering of the Au deposit by the high energy species produced by PLD. When the combination of PLD of Au and MS of ZnO was performed, a similar increment was observed in the emission intensity, but in this case of neutral Zn that was caused by the preferential resputtering of Zn from the ZnO–Au deposit. The MS plasma neither significantly affect the PLD plasma expansion nor did it affect the resputtering of the films.

In recent years $\beta $ -Ga2O3 thin films and crystals have gained attention as excellent candidates for transparent and high-power applications due to its wide band gap (4.6 – 4.9 eV) and large breakdown field (~8 mV/cm). However, $\beta $ -Ga2O3 single crystals and highly crystalline $\beta $ -Ga2O3 thin films require high temperature, long processing times and, often, expensive tools that limit integration with other technologies. Amorphous Ga2O3 has not been studied as intensely as $\beta $ -Ga2O3 and mostly metal-semiconductor-metal (MSM) structures and diodes using this material have been reported. In this paper, we discuss a simple and economical method to fabricate thin film transistors (TFTs) based on un-doped amorphous Ga2O3 thin films deposited at room temperature by magnetron sputtering. Control of the Ga2O3 thin films resistivity over a wide range is demonstrated by controlling the deposition power and pressure. The TFTs show a threshold voltage ( $\text{V}_{{\mathrm {T}}}$ ) of 0.92 V, saturation mobility ( $\mu _{{\mathrm {sat}}}$ ) of 0.511 cm2/ $\text{V}\cdot \text{s}$ and subthreshold slope (SS) of 83.62 mV/dec. More importantly, these devices have been evaluated as phototransistors, which has not been intensely studied yet. The phototransistors tested under DUV radiation exhibited a rejection ratio UV-Visible of 103 and responsivity of $10^{2}\text{A}$ /W ( $\text{V}_{{\mathrm {G}}} =0$ V) and 104 A/W ( $\text{V}_{{\mathrm {G}}} =6$ V), gain of 103, specific detectivity of 1015 Jones and a photosensitivity of 107.

An extensive study of the effect of various technological factors on the electrical properties of ZnO thin films obtained by DC magnetron sputtering of ZnO:Ga:Cl ceramic targets on glass substrates has been carried out. The effect of deposition temperature, film thickness, growth rate, background pressure, working gas pressure, preliminary slow-growing and undoped layers, stoichiometric deviation, and Ga and Cl concentrations has been studied. Changes in the growth rate, transparency in the ultraviolet and visible spectral ranges, morphology, crystallinity, and crystallite size have also been analyzed. It has been shown that the effect of co-doping with Cl is most significant at the lowest temperatures, which can decrease the resistivity of the films by 2 times at a deposition temperature of 100 °C. Zinc oxide thin films with a resistivity of 2.5 × 10− 4 Ω⋅cm and a figure of merit of 31 kΩ− 1 have been successfully obtained. A theoretical model taking into account various types of mobile gallium chlorides has been proposed to elucidate the advantage of co-doping with Cl.

The structural and nanomechanical properties of Cu(InxGa1–x)Se2 films deposited on Si(100) substrate at different temperatures (25°C to 500°C) by one-step radiofrequency magnetron sputtering are discussed. X-ray diffraction analysis revealed a dominant (112) diffraction peak. The surface morphology was examined by field-emission scanning electron microscopy and atomic force microscopy. The film composition was examined by electron probe microanalysis. The Cu/(In + Ga) and Ga/(In + Ga) ratios were 0.9 and 0.3, respectively. Nanoindentation conducted in conjunction with scanning electron microscopy revealed that the films suffered severe delamination-type fracture due to poor adhesion to the Si substrate. The hardness of the films was not influenced by the substrate temperature except for the film grown at 500°C. The hardness was greatly affected at depths greater than the thickness of the film due to its poor adhesion. At deep indents, the hardness results agreed closely with that of the Si substrate.

Co1–xTix (x = 0.3, 0.5 and 0.7) thin films were prepared on Si (100) substrate using DC-magnetron sputtering deposition technique. A structural phase transition occurs from hexagonal to cubic cryst...

In this work, the sensing membrane of extended-gate field-effect-transistor (EG-FET) sensor with zinc oxide (ZnO) nanorods (NRs) and Au adsorbed on ZnO NRs were fabricated by hydrothermal method and DC magnetron sputtering. The Pt sheet as a reference electrode, put in sensing membrane and reference electrode to defferent pH valuse buffer solution for linearity and sensitivity analysis. Results showed the both of the ZnO based EG-FET pH sensors exhibited high linearity and sensitivity, and Au-adsorbed exhibited significantly improved sensing performance, the average voltage sensitivity and average current sensitivity of the ZnO NRs based EG-FET sensor was 24.67 mV/pH and $21.4~\mu \text{A}$ /pH, and linearity was 0.986 and 0.994, whereas that of the Au-adsorbed ZnO NRs based EG-FET pH sensor was 76.75 mV/pH and $45.66~\mu \text{A}$ /pH with a linearity of 0.990 and 0.980.

As a typical thermochromic material, Vanadium dioxide (VO2) exhibits unique optical and electrical properties. High-quality VO2 thin film was prepared by DC reactive magnetron sputtering and in situ annealing. The results show that the heating process transition temperature is 67 °C and the cooling process transition temperature is 49 °C after heating film from 25 to 90 °C. The low transition temperature of 58 °C is obtained, which is lower than 68 °C of VO2 crystal. In the visible region, all the transmittance between 608 and 780 nm can be greater than 40%, and the maximum visible transmittance was achieved to proximal 45%. At temperature of 90 °C and incident wavelength of 2.5 µm, the large optical transmittance contrasts of 52% were obtained. Raman spectroscopy with different temperatures was used to verify the structure evolution with phase transition. Our results show that high visible transmittance and relatively low transition temperature of VO2 film on quartz substrate can be directly obtained by DC reactive magnetron sputtering and in situ annealing.

In this study, a surface-enhanced Raman scattering (SERS) substrate based on uniform silver nanoparticles/pyramidal silicon arrays (Ag NPs/PSi) is prepared by combining of wet etching processes and magnetron sputtering method. The average size of the Ag NPs is about 30–50 nm and uniform distribution on the surface of the PSi which are beneficial to the sensitivity and stability of the SERS signal. For R6G probe, a significant enhancement has been obtained even for the lowest concentration of 10−10 M. For abamectin detection, the Ag NPs/PSi substrate has exhibited sensitivity as low concentration as 1 ppm. The vibration peaks of abamectin molecules are firstly identified and investigated.

Cuprous oxide (Cu2O) has been formed on glass substrates by dc reactive magnetron sputtering method, whereas pure target of the solid copper was sputtered with a mixture of plasma for argon gas and oxygen gas was used to form these films. Under vacuum chamber pressure of 1.2×10-5 Pa, thin film thickness was changed from 100 nm to 300 nm while other deposition parameters were fixed. The influence of changing the thickness of thin films on the electrical and the optical properties was investigated in this study. X-ray photoelectron spectroscopy (XPS), X-ray Diffractions system XRD, Atomic Force Microscopy (AFM), hall effect measurement system, UV–VIS spectrophotometer were employed to determine the characteristic of the deposited thin films. Thin film of 200 nm has observed low resistivity of 60.63 Ω cm and direct band gap of 2.5eV. This study has demonstrated that the thickness has direct influence on electrical and optical properties. http://dx.doi.org/10.30572/2018/kje/090109

Тонкие пленки теллурида кадмия (CdTe) относятся к соединениям AII BVI, демонстрируют полупроводниковые свойства и представляют собой важную область исследований из-за их широкого применения в различных оптоэлектронных устройствах. Солнечные элементы на основе CdTe привлекают внимание, поскольку CdTe характеризуется прямой энергетической запрещенной зоной Eg и высоким коэффициентом поглощения, что делает CdTe отличным светопоглощающим слоем солнечных элементов. Испарение материала в вакууме методом высокочастотного магнетронного распыления является одним из наиболее эффективных методов получения однородных пленок. Настоящая работа посвящена исследованию оптических свойств тонкой пленки CdTe, полученной на кварцевой подложке методом высокочастотного магнетронного распыления. Определены спектры оптического пропускания, отражения и µ-комбинационного рассеяния тонкой пленки CdTe. Линейность спектральной зависимости коэффициента оптического поглощения a тонкой пленки CdTe в координатах (ahν)2 vs hν свидетельствует о прямом характере оптических переходов, соответствующих длинноволновому краю фундаментального поглощения. Оптическая ширина запрещенной зоны исследуемой тонкой пленки CdTe составляет Eg = 1,53 эВ. Пики экспериментальных спектров комбинационного рассеяния света при 121; 139; 142; 167 и 331 см–1 приписываются фононам в кристаллических CdTe и Te.

International audience; The p-type Ge-doped (0, 1, 4 and 7 at.%) Mg

The influence of film thickness on the structural and optical properties of silicon dioxide (SiO2) and zinc oxide (ZnO) thin films deposited by radio frequency magnetron sputtering on quartz substrates was investigated. The deposition conditions were optimized to achieve stoichiometric thin films. The orientation of crystallites, structure, and composition were investigated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), while the surface topography of the samples was analyzed using scanning electron microscopy (SEM). The optical characteristics were measured for samples with the same composition but obtained with different deposition parameters, such as increasing thickness. The optical constants (i.e., the refractive index n, the extinction coefficient k, and the absorption coefficient α) of the SiO2 and ZnO oxide films were determined from the transmission spectra recorded in the range of 190–2500 nm by using the Swanepoel method, while the energy bandgap was calculated from the absorption spectra. The influence of thickness on the structural and optical properties of the oxide films was investigated. Good optical quality and performance were noticed, which makes these thin films worthy of integration into metamaterial structures.

Modulating the magnetic anisotropy of ferromagnetic thin films is crucial for constructing high-density and energy efficient magnetic memory devices. Ta/W(N)/Co/Pt multilayers were deposited on silicon substrates by magnetron sputtering at room temperature. The influences of N dopant on the magnetic anisotropy of the multilayers were investigated by preparing the sample with N incorporation. The results indicate that when sputtering W target with only argon gas (Ar), Ta/W/Co/Pt sample shows in-plane magnetic anisotropy (IMA). When sputtering W target at a different amount of N2 and Ar atmosphere, it can induce perpendicular magnetic anisotropy (PMA) for proper N-doped Ta/W(N)/Co/Pt sample. When the gas flow ratio of Ar:N2 is 16:6, the effective magnetic anisotropy constant reach its maximum value of 1.68 × 105 J·m−3, which enhanced by about 400% than our past works (annealing treatment is necessary to induce PMA in Pt/Co/MgO system). X-ray diffraction (XRD) and X-ray reflection (XRR) results demonstrate that N dopants can effectively promote the formation of β-W phase and reduce the roughness of W(N)/Co interface, which are beneficial for PMA. X-ray electron spectroscopy (XPS) analysis reveals that N doping redistributes Co charges, nitrogen ions participate in electron allocation of Co and attract some electrons of Co to form orbital hybridization between Co 3d and N 2p. This may be another important reason for the PMA formation.

The impact of annealing on luminescence properties of radio-frequency magnetron sputtering grown alumina films and their possible application in radiation measurement are presented. Here, grazing incidence X-ray diffraction study reveals the growth of amorphous alumina films, while the annealing treatment results in the gradual formation of nanocrystallites. They are found to be embedded in the amorphous matrix by cross-sectional Transmission Electron Microscopy for 1200 °C annealed thin film. The evolution of self-patterned wrinkles has also been observed at the surface by Scanning Electron Microscopy. A comprehensive analysis of optically active defect centers is carried out by room temperature photoluminescence (PL) measurement. This indicates a monotonic increase of oxygen vacancies (F centers) with increasing annealing temperature up to 1200 °C, though they are not directly correlated with the thermoluminescence (TL) results after exposing them to gamma radiation from a 60Co source. Based on PL analysis, the TL glow curves with increasing annealing temperature are elucidated in the light of the involvement of both trap centers and F-type recombination centers residing at grain boundaries. In terms of TL results, 1200 °C annealed alumina film is found to be superior to both the as-grown film, and the one annealed at 1100 °C. Finally, the linear TL response curves in the 1200 °C annealed film after exposing to both gamma radiation (up to 5 kGy) and energetic charged particles (80 MeV carbon ions) are demonstrated up to 130 kGy.

A sensor sensitive to acetone vapors based on a Fe2O3❬Sn❭ metal oxide solid solution was fabricated by high-frequency magnetron sputtering. The gas-sensitivity of the manufactured sensor are investigated. The Fe2O3❬Sn❭ sensor shows sensitivity to acetone vapors starting from a temperature of 150°C under the influence of ultraviolet rays. The increase in operating temperature was accompanied by a linear increase in the sensor response. Exposure to ultraviolet rays not only improved the sensitivity of the sensor under study, but also increased its performance. A sensor based on Fe2O3❬Sn❭ can be successfully applied in acetone detectors.

Sb-rich Sb55Te45 alloy thin films were prepared by magnetron sputtering. The amorphous–crystalline transition of thin films was studied by an in situ resistance–temperature measurement system. The bandgap of Sb55Te45 film was measured by spectrophotometer. The surface morphologies and phase diagrams of thin films with temperature were observed by atomic force microscope. The phase structure of the thin film was observed by X-ray diffraction. The bond structure of thin films before and after crystallization was observed by Raman spectroscopy. The velocity of reversible phase transition of thin films was studied by laser picosecond detection technique. The results showed that Sb55Te45 thin film had good thermal stability and rapid phase change rate. It is a potential high-speed phase change material.

TiN thin films have been deposited by magnetron sputtering (DC) method under pure argon (100% Ar) gas for different times at 100 oC temperature. Additionally, three substrate types have been used: Low Carbon Steel (LCS), Stainless Steel (SS304) and Silicon of (100) orientation. The composition of the films has been verified by Energy Depressive X-ray Spectroscopy (EDX) analysis for films deposited on Si substrate. This analysis has proved that the nitride films TiN was sub stoichiometry, Scanning Electron Microscope (SEM) image was used to estimate the thickness of TiN/Si film. X-ray diffraction (XRD) measurements were also applied to investigate the orientations of films. All the films (coated samples) have shown enhanced corrosion resistance compared with virgin SS304 and LCS substrate (noncoated sample) in 3.5% NaCl at 25 oC (equivalent to seawater). Morphological behavior was investigated by means of Atomic Force Microscopy (AFM), which indicates very smooth films and consequently related with corrosion resistance using Tafel and the electrochemical impedance spectroscopy (EIS) measurements. It was found the thinner film has revealed higher corrosion resistance and low roughness. DOI: http://dx.doi.org/10.17807/orbital.v13i1.1577

—The Ti–Al–C and Ti–Al–Si–C films have been deposited on Si(100) substrates by dual DC magnetron sputtering of the Ti–Al composite, graphite, and SiC targets at various sputtering currents. The effects of the sputtering current and annealing temperature on the structural, compositional, and mechanical properties of the films have been studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and hardness measurements. The as-deposited films are amorphous and exhibit low values of the root mean square roughness (0.25–0.27 nm). The results of XRD and XPS studies and first-principles calculations confirm that the annealing at 800°C leads to the formation of the crystalline Ti2AlC MAX, Al4C3, TiC2, and TiO2 phases and the amorphous Al–C–O phases, and the crystalline Ti2Si1 – xAlxC MAX, Al4C3, and TiSi/TiSi2 phases and the amorphous Al–Si–C–O phases in the Ti–Al–C and Ti–Al–Si–C films, respectively. The amorphous films exhibit an increase in the hardness with an increase in the sputtering current at the graphite or SiC targets, which reaches maximum values of 19.1 and 17.8 GPa for the Ti–Al–C and Ti–Al–Si–C films, respectively. The observed changes in the hardness are explained by the evolution of chemical bonds.

In this article, the effects of the O2 ratio on the electrical characteristics, including the I-V characteristic curve, Panchen’s curve, and I-P curve, were tested in a sample of O2/Ar gaseous mixture . The sample was produced by plasma-based DC magnetron sputtering with niobium metal as a target material. The inter-electrode spacing value was 4 cm. Plasma diagnosis via the Optical Emission Spectroscopy (OES) method was used to achieve Te and Ne mixture values of 20 %, 30 %, 50%, and 70% in the Ar/O2 system. The results showed that the discharge is operating in the abnormal glow region and the discharge current was decreased by increasing O2 percentage. In addition, the experimental results showed that the discharge is optimal at 30% gas ratio. It was found that the electron temperature was decreased with increasing working pressure and increased with increasing the O2 percentage, while electron density was increased with increasing both working gas pressure and O2 percentage.

The formation of nickel silicide layers on (111)-Si substrates during rapid thermal annealing in the heat balance mode was studied by the Rutherford backscattering method, X-ray diffraction, transmission electron microscopy, and electrophysical measurements. Nickel films of about 70 nm thickness were deposited by magnetron sputtering at room temperature. The rapid thermal treatment was carried out in a heat balance mode by irradiating the substrates backside with a non-coherent light flux of quartz halogen lamps in the nitrogen medium for 7 seconds up to the temperature range of 200 to 550 °C. The redistribution of nickel and silicon atoms to monosilicide NiSi composition starts already at a temperature of 300 °С and almost ends at a temperature of 400 °С. In the same temperature range, the orthorhombic NiSi phase with an average grain size of about 0.05–0.1 μm is formed. At a rapid thermal treatment temperature of 300 °C, two phases of silicides (Ni2 Si and NiSi) are formed, while a thin layer of unreacted Ni is retained on the surface. This fact can be explained by the high heating rate at the initial annealing stage, at which the temperature conditions of the NiSi phase formation occur earlier than the entire Ni layer manages to turn into the Ni2 Si phase. The layers with a simultaneous presence of three phases are characterized by a high roughness of the silicide-silicon interface. The dependence of the specific resistivity of nickel silicide layers shows an increase to the values of 26–30 μOhm · cm in the range of rapid thermal treatment temperatures of 200–250 °C and a subsequent decrease to the values of about 15 μOhm · cm at a rapid thermal treatment temperature of 400 °C. This value of specific resistivity is characteristic of the high conductivity of the NiSi phase and correlates well with the results of structure studies.

We introduce a technique for the directed transfer of molecules from an adjacent reservoir onto a sample surface inside the vacuum chamber of a ToF-SIMS instrument using gas cluster ion beam (GCIB) sputtering. An example application for in situ matrix-enhanced secondary ion mass spectrometry (ME SIMS) is provided. This protocol has attractive features since most modern SIMS instruments are equipped with a GCIB gun. No solvents are required that would delocalize analytes at the surface, and the transfer of matrix molecules can be interlaced with SIMS depth profiling and 3D imaging sputtering and analysis cycles, which is not possible with conventional ME SIMS strategies. The amount of molecular deposition can be finely tuned, which is important for such a surface sensitive technique as SIMS. To demonstrate the concept, we used 2,5-DHB as a matrix for the enhancement of three drug molecules embedded in a tissue homogenate. By automatic operation of sputter deposition and erosion (cleanup) cycles, depth profiling could be achieved with ME SIMS with good repeatability (

Cobalt-iron thin film was deposited on rotating silicon (100) substrate using the DC-magnetron sputtering deposition unit. The structure is examined by Grazing Incidence X-ray Diffraction and resul...

In this investigation ZnFe2O4 thin films were fabricated by RF magnetron sputtering and the magnetic behavior was examined under the influence of the growth conditions in three types of atmospheres, using near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and vibrating sample magnetometry (VSM). XPS revealed that films under an Ar/O2 ratio 1:2 and 2:1 have Fe/Zn atomic ratios similar to the Fe/Zn stoichiometric composition; while the films deposited in pure Ar atmosphere, showed a formation of Fe ions (Fe0) reduced by Ar ion sputtering. VSM revealed an enhancing of the saturation magnetization for the ZFO in thin films unlike the samples in bulk, suggesting that Fe ions migrate to A sites and the interaction JAB dominates the magnetic properties instead of JBB interaction.

In this study, Cu2ZnSnS4 (CZTS) thin films are deposited onto the glass slides via the radio frequency (RF) magnetron sputtering, and subsequently sulfurized at different heating rates of 5 °C/min, 20 °C/min, 35 °C/min and 50 °C/min, respectively. The disorder degrees and the secondary phases of finally obtained CZTS thin films are then systematically investigated by using scanning electron microscopy, X-ray diffraction, energy dispersive X-ray, Raman spectroscopy, Raman mapping, UV–vis–NIR spectroscopy, and the Hall effect measurement system. The morphological, structural, and electrical properties of fabricated CZTS films affected by the heating rate are subsequently evaluated. The heating rate of 20 °C/min during the sulfurization process is found to produce a nearly single-phase kesterite CZTS with a substantially low disorder degree. However, more Cu2-xS and Cu3SnS3 secondary phases are found in samples that are annealed at other heating rates. The effect of heating rate on the decomposition during the sulfurization process is also studied and then elaborated. This study provides an optimal condition for minimizing the secondary phases and disorders, in other words, providing the idea process condition to manufacture the high-quality CZTS thin films for solar cells with high conversion efficiency.

Permalloy (NiFe) thin films were prepared by direct current (DC) magnetron sputtering (MS). XRD, EDS, AFM, PPMS, Hall effect Test Station, UV–Vis spectrometer , and spectroscopic ellipsometer (SE) were used to characterize the microstructure, electrical, magnetic and optical properties of the films. Magnetic anisotropy was observed in NiFe films grown on , and -STO substrates, and among them , NiFe/STO showed higher saturation magnetization $${M_{\rm{s}}}$$ = 8.4 emu/g , residual magnetization $${M_{\rm{r}}}$$ = 6.625 emu/g and smaller coercivity $${H_{\rm{c}}}$$ = 28 Oe. Films grown at 300° C exhibit stronger magnetization, smaller sheet resistance ( $${R_{\rm{s}}}$$ ), resistivity ( $${\rho }$$ ), and optical reflectivity ( $${R\%}$$ ) growth relative to room temperature (RT). Greater absorption (A) and smaller reflection at 230 nm . showed better transmittance ( $${T\%}$$ ) at 336 nm. Finally, the characterization results using the a spectroscopic ellipsometer are also given.

Amorphous lithium niobate (LiNbO3) films with the direct optical bandgap close to the bulk LiNbO3 were fabricated by radio-frequency magnetron sputtering (RFMS) technique in an Ar, Ar(90%) + O2(10%), and Ar(60%) + O2(40%) reactive gas environments. LiNbO3 films synthesized in an Ar(60%) + O2(40%) gas mixture manifest a higher magnitude of the indirect optical bandgap due to a higher defect concentration. The pulsed photon treatment (PPT) leads to the crystallization of the as-grown LiNbO3 films affecting the indirect bandgap Egindir more efficiently compared to the conventional thermal annealing. PPT influences Egindir of the studied films oppositely: it decreases Egindir for the films grown in an Ar and Ar(90%) + O2(10%) environments, whereas Egindir is decreased for the films synthesized in an Ar(60%) + O2(40%) gas mixture after PPT.

In this work, we have investigated the electrical characteristics of Zn/ZnO/n-Si/Au-Sb Schottky diodes before and after different doses (25 and 50 Gray) of electron-irradiation at room temperature. Initially, the ohmic contact has been made on n-Si semiconductor with Au-Sb alloy. After this process the ZnO thin film was grown on n-Si semiconductor by using RF magnetron sputtering system, and then the contact area is determined by sputtered Zn metal to surface of ZnO in DC sputtering system at about 10-6 Torr. The characteristic parameters of the junction such as ideality factor and barrier height values are calculated from I to V measurements and the carrier concentration, Fermi energy, diffusion potential, and barrier height values are calculated from reverse bias C-2–V measurements at various frequencies and room temperature. The I–V and C–V measurements of these diodes performed at room temperature and in dark. Experimental results showed that the values of the ideality factor increased and barrier height from forward-bias I–V measurements decreased and diffusion potential and the values of the barrier height obtained from reverse-bias C–V measurements decreased after electron-irradiation. However, changes in the characteristic parameters of the ZnO interfacial layer diode in 25 Gray of electron-irradiation were found to be less than those of the 50 Gray of electron-irradiation.

In this work, we have studied the electrical characteristics of Zn/n-Si/Au-Sb Schottky diodes before and after different doses (25, 50 and 75 Gray) of electron-irradiation at room temperature. The ohmic contact has been made on n-Si crystal with Au-Sb alloy. The rectifier contact was sputtered Zinc metal on n-Si by using DC magnetron sputtering. The I–V measurements of these diodes performed by the use of a KEITLEY 487 Picoammeter/Voltage Source and the C–V measurements were performed with HP 4192A (50–13 MHz) LF Impedance Analyzer at room temperature and in dark. Experimental results showed that the values of the ideality factor obtained from I to V measurements increased and the values of the barrier height obtained from I to V and C–V measurements decreased after electron-irradiation.

(Ta2O5)1-x-(TiO2)x (TTO) thin films, with x = 0.035, were deposited onto the P/boron-silicon (100) semiconducting substrates by reactive direct current (DC) magnetron sputtering of mosaic Ta and Ti metal targets, at ambient temperature. As-deposited films have been passed through the process of annealing at the temperatures, ranging from 500 to 800 °C. X-ray diffraction measurements, generally, show the formation of Ta2O5 structure of the annealed films. Metal–oxide–semiconductor (MOS) structure of Ag/(Ta2O5)1-x-(TiO2)x/p-Si (Ag/TTO/p-Si), with x = 0.035, was formed, and capacitance of the structure was measured, at room temperature and 1 MHz. Capacitance of prepared MOS structure was measured, and found generally, increasing with annealing temperature. Among the prepared films, maximum value of dielectric constant was found 45, at 1 MHz, for the films annealed at 700 °C. Frequency dependent behaviour of dielectric loss was observed, and was found minimum value of 0.022, at 200 kHz, for the films deposited at room temperature.

Films of Li2O and Li2S grown by sputter deposition exhibit Li+ conductivity values at room temperature which are enhanced by 3–4 orders of magnitude relative to bulk samples. Possible mechanisms are discussed. The results may help explain the ion transport pathway through passivation layers containing these chalcogenides in batteries.