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The carbon nanotubes grafted methylene blue molecularly imprinted polymers (CNT-MB-MIPs) were prepared by grafting aminated carbon nanotubes (CNTs) and copolymerized in the presence of template molecules methylene blue (MB), functional monomers, crosslinkers, and initiators. The results from structural analyses indicate that CNTs were successfully grafted onto the molecularly imprinted polymers (MIPs). The adsorption experiments showed that the adsorption capacity can be affected by grafting CNTs. The adsorption capacity of CNT-MB-MIPs on MB can reach 2793[Formula: see text]mg[Formula: see text]g[Formula: see text] while the initial concentration of MB was 12[Formula: see text]g[Formula: see text]L[Formula: see text], which was higher than that of MB molecularly imprinted polymers (MB-MIPs). Meanwhile, compared with MB-MIPs, CNT-MB-MIPs had a lower adsorption capacity for iron ions, indicating that CNT-MB-MIPs could inhibit the adsorption of iron ions. Adsorption kinetics study showed that the adsorption mechanism of the polymer for MB was in good agreement with the quasi-second-order kinetics model ([Formula: see text]) and the adsorption mechanism for iron ions was also in good agreement with the Bangham kinetics model ([Formula: see text]). The adsorption isotherm showed that the adsorption process of the two adsorbents was mainly monolayer chemisorption. The remarkable adsorption capacity of CNT-MB-MIPs may be due to the enlargement of adsorption sites on MIPs surface by CNT-NH2 grafting. At the same time, it can inhibit the adsorption of iron ions, because part of the carboxyl groups in CNT-MB-MIPs are bonded by CNTs, led to few carboxyl groups sites left for adsorbing iron ions, thereby the complex between carboxyl groups and iron ions were inhibited.

This study aimed to develop a novel magnetic chitosan/dopamine/Fe3O4 nano-adsorber (CS@PDA@Fe3O4) for the removal of heavy metal ions and organic dye molecules from aqueous solution. CS@PDA@Fe3O4 was prepared by surface modification of PDA/Fe3O4 nanoparticles with chitosan using IPTES as the cross-linker. The surface structure, composition, and properties of the CS@PDA@Fe3O4 nano-adsorber were characterized by elemental (EDS), spectroscopic (XRD, XPS, and FT-IR), magnetic intensity (VSM), surface and morphological (TEM and SEM) analyses. In order to study its adsorption behavior, equilibrium and kinetics studies were carried out through batch experiments. Additionally, the influences of the pH value, initial concentration, adsorbent dose, and contact time were also evaluated. The CS@PDA@Fe3O4 nano-adsorber exhibited high adsorption capacity especially for Cu(II), with a maximum adsorption capacity of 419.6 mg g−1. The experimental data were well described by the Langmuir isotherm kinetic models.

Topological magnetic domains exhibit many fascinating features and great potential in information storage and spintronics owing to their unique spin textures. In order to investigate the topological properties of the domain structures, the spontaneous evolutions of magnetic moments are evaluated by using Landau–Lifshitz–Gilbert equation. The equilibrium phase diagrams of the system with randomly, radial and axial distributed initial magnetic moments have been studied in detail. Simulation results show that the changes of quality factor (Q) and aspect ratio (T/D) lead to great differences in magnetization process under different initial magnetization states. Vortex, biskyrmion, skyrmion and bubble are formed as the value of Q gradually increases from 0 to 1. The system with Q 1.0 are arranged along the easy axis. When Q and T/D are in the range of 0.6 ~ 0.8 and 0.10 ~ 0.16, respectively, it is conducive to the formation of nontrivial topological domain. Biskyrmion is spontaneously formed in the system of Q = 0.6 and T/D = 0.12, proving that skyrmion-like domain can be generated in the absence of Dzyaloshinskii–Moriya interaction or external field.

Tailoring magnetic anisotropy of ferromagnetic films is a critical issue in constructing energy-efficient and high-density magnetic memory devices. Presently, the effective tunability was focused on a single-ion-manipulated electronic structure evolution. Here, we reported a new strategy of dual-ion-tuned orbital structure and magnetic anisotropy of ferromagnetic films. N-doped Fe/MgO bilayer films were deposited on shape memory alloy substrates which can generate a significant lattice strain on the films. Before the N ions participate into the manipulation, the Fe/MgO film shows an in-plane magnetic anisotropy, which may be due to excessive Fe-O orbital hybridization. Interestingly, the N and O ions synergistically manipulate electronic coordination of the Fe layer, which can be further modified by the lattice strain through a charge transfer among N-Fe-O. Under such effect, the magnetic anisotropy of the film is switchable from in-plane to perpendicular magnetic anisotropy (PMA). The X-ray line dichroism (XLD) characterization reveals that the anisotropy regulation is related to Fe 3d orbital evolution: N-Fe orbital hybridization promotes the Fe d

This study aimed to develop a novel magnetic chitosan/dopamine/Fe

The high-entropy concept has been recently proposed to be a promising paradigm to enhance the magnetocaloric properties of materials. Motivated by this, the magnetic properties and the magnetocaloric performance of two high-entropy perovskites (Dy1/4Ho1/4Er1/4Tb1/4)FeO3 and (Gd1/5Dy1/5Ho1/5Er1/5Tb1/5)FeO3 have been investigated. The magnetic measurements indicate that a spin-glass phase occurs at low temperatures in the high-entropy compounds, which is induced by the strong compositional disorder of rare-earth sublattice. The glassy state can lead to a sluggish magnetic transition and consequently a potential improvement in the magnetocaloric performance. Due to the increase in configurational entropy, large refrigerant capacity of 247 and 203 J/kg for a magnetic field change of 70 kOe is obtained in the (Gd1/5Dy1/5Ho1/5Er1/5Tb1/5)FeO3 and (Dy1/4Ho1/4Er1/4Tb1/4)FeO3 compounds, respectively. Our findings highlight the availability of spin order control through tuning the configurational entropy and demonstrate the key role of high-entropy design in enhancing the magnetocaloric properties of materials.

The Co/Pt multilayers with Pt and MgO/Pt underlayer were prepared by magnetron sputtering and the perpendicular magnetic anisotropy(PMA) of the multilayers were researched by the means of Anomalous Hall effect (AHE). The annealing effect study of Pt(1.0)/[Co(0.4)/Pt(0.8)]3(unit: nm) shows that the sample has pretty good thermal stability but the coercivity(HC) has little change. The experimental results show that the PMA and Hc of Co/Pt multilayers was improved greatly by the additional scattering of electrons induce from the amorphous insulator-metal interface of MgO-Pt. When MgO layer thickness(tMgO) is 4nm, the Hall resistance (RHall) of MgO(4)/Pt(1.0)/[Co(0.4)/Pt(0.8)]3 multilayer has a maximum value of 2.11Ω which is increased by 16%. Furthermore the Hc increases to 172Oe which is more than 1.5 times to Pt(1.0)/[Co(0.4)/Pt(0.8)]3 multilaye and the Hc meets the maximum value of 204Oe when tMgO is 2 nm. Annealing effects of MgO(4)/Pt(2)/Co(0.2)/Ni(0.4)/Co(0.2)/Pt(2) show that it has good therma...

The regulation in the magnetic anisotropy of magnetic films is crucial for developing the magnetic storage and logic devices. The traditional work achieved an effective tunability of the magnetic anisotropy by a subsequent processing of the as-deposited film, such as a post-annealing treatment or electric field application. Here, we proposed an effective method to achieve a direct and broad tunability of the magnetic anisotropy in the as-prepared film by adjusting electronic coordination. Nitrogen (N) atoms were doped in the Co layer of Pt/Co/MgO multilayers to effectively control the electronic coordination of Co and enhance the 3dz2–r2 orbital occupancy of Co for modulating the Co–O orbital hybridization. Consequently, the magnetic anisotropy of the as-deposited film changed from in-plane to perpendicular direction with the N doping, resulting in a significant increment in the magnetic anisotropy energy by 2.48 × 106 erg/cm3. Furthermore, the critical Co thickness with maintaining the perpendicular magnetic anisotropy was enlarged from 1 to 3 nm, which is beneficial for enhancing the stability of nanodevices. These findings provide an effective strategy to tune the magnetic anisotropy of magnetic films toward the applications of various magnetic storage and logic devices.

Co/Ni multilayers have important application in magnetic random access memories(MRAM) and spin transfer torque(STT). The perpendicular magnetic anisotropy(PMA) of Pt based with Ta inserted Co/Ni multilayers which prepared by magnetron sputtering technique was studied in this article and the thickness of Ta was modulated. The PMA of the samples become better significantly as Ta inserted in the under layer and the squareness is optimum when the inserted Ta is 1 nm. The periodical number n was also modulated and the samples have good PMA all with n changed from 1 to 4. The squareness is best, moreover, the hall resistance is maximum when n is 4. Finally, the optimum sample was obtained as Ta(1 nm)/Pt(5 nm)/Co(0.3 nm)/Ni(0.6 nm) /Co(0.3)/Pt(3 nm).

Tailoring the magnetic anisotropy and magnetization switching of a ferromagnetic film is crucial in constructing an energy-efficient magnetic random access memory (MRAM). Fe16N2 alloy was predicted to bear giant magnetic anisotropy and high spin polarization ratio in theory and is a promising material to be applied in the magnetic memory devices. However, the related research work was scarcely reported. In this work, we devised a Fe/Cr/FeN/Cr heterostructure to introduce a controllable strain on the FeN layer by a lattice mismatch. The strain is variable with the thickness of FeN layer and can modify the phase constituent in the FeN layer effectively. By using the strain engineering, we achieved a broad tunability of magnetic anisotropy energy ranging 0.1—0.7 × 106 J/m3. Based on the anisotropy modulation, we achieved electrical control of partial magnetization switching in the Fe/Cr/FeN/Pt heterostructure by a spin-orbit-toque (SOT) effect under a current density ~1010 A/m2. These findings may provide a promising ferromagnetic material for realizing energy-efficient SOT-MARM.

Compare with Ce–Fe–B crystalline magnets, the amorphous alloy exhibit interesting properties due to their domains, low anisotropy energy, and microstructure contribution. In order to investigate magnetic properties and microstructures of the amorphous Ce–Fe–B system with Co substituting for Fe, the ribbons with a nominal composition of Ce13.5(Fe79.5-xCox)B7 (x = 0, 3, 6, 9, 12) were prepared using vacuum melt spinner at a wheel speed of 50 m/s. The XRD and the corresponding SAED Pattern indicate the uniform amorphous microstructure is well maintained in each sample. These ribbons are magnetically soft and undergo a second order phase transition from ferromagnetic to paramagnetic state. With the increasing Co content, the Curie temperature almost linearly increases with temperature during 270 K and 410 K. Results from Lorentz Transmission Electron Microscopy (L-TEM) and micromagnetic simulation prove that the vortex domains can form spontaneously and stability in Ce–Fe–B amorphous materials no matter doping Co or not. The nontrivial topological domain structures found in experiments and numerical calculations have potential applications in the field of information storage, which is helpful to develop new applications of high abundance rare earth elements in functional materials.

A structure of Pt/ [Co/Ni]2/Au/ [Co/Pt]N with perpendicular magnetic anisotropy was prepared successfully by magnetron sputtering technique. The magnetic properties dependence of Au thicknesses and [Co/Pt] layer repetition number have been studied. The results show that when the [Co/Pt] layer repetition number is 4, the strongest coupling among the samples occurs when the Au layer is 3 nm for its largest Hall voltage and large switching field plateau. The Hall loop of the sample has obvious perpendicular magnetic anisotropy. The magnetoresistance of Pt/ [Co/Ni]2/Au(t)/ [Co/Pt]4 has vibration behaviour due to the Ruderman-Kittel-Kasuya-Yosida interaction with the increase of tAu. As the thickness of the Au spacer is determined to be 3 nm, the study of dependence of [Co/Pt] layer repetition number to the magnetic properties shows that the N has significant influence to the magnetoresistance of the multilayer films. When N is 5, the MR of the sample has the maximum value and the optimum sample is str...

FePt thin films in the thickness range of 5∼40 nm, have been prepared by magnetron sputtering on MgO (001) substrates. The magnetic measurements have shown that the decrease in the thickness is helpful to improve perpendicular anisotropy of FePt thin films. The perpendicular anisotropy gradually changes to in-plane anisotropy with increase in the thickness leading to weaker (001) texture of FePt thin film. After vacuum annealing at 600°C, the 5 nm thick FePt thin film has been obtained with about 240 kA/m of perpendicular coercivity, good squareness and only about 7nm of average crystalline size, which is suitable for applications of future ultra high density perpendicular magnetic recording.

The perpendicular magnetic anisotropy (PMA) of Pt(t1Pt)/[Co(tCo)/Pt(t2Pt)]n which prepared by magnetron sputtering technique was studied in this article. The impact to PMA and magnetic properties of Co/Pt multilayers was investigated from the aspects of Co layer thicknesses tCo, Pt inner layer thicknesses t2Pt, Pt underlayer thicknesses t1Pt and periodic number n. The test results show that interfacial effects are the main factors which influence the PMA and other macroscopic properties of the samples. From comparison of the test results of magnetic properties the best multilayer structure Pt 1.0 nm/(Co 0.4 nm/Pt 0.8 nm)3 was obtained. Anisotropic energy of the best sample was 2.0 × 105 J.m−3 which indicated that it has good perpendicular magnetic anisotropy.

Single phase Fe16N2 is a potential material in building high-performance magnetic writing heads and permanent magnets due to its ultra-high saturation magnetization (MS) and magnetic anisotropy (Keff). However, the poor controllability of phase constituent and low thermostability (decomposed at 200 °C) are big obstacles to its practical applications. In this work, we have devised a novel Fe/Cr/FeN:Co heterostructure to introduce both lattice strain and Co doping for tuning the FeN constituent and enhancing the phase stability synergistically. With effective regulation, the FeN layer can possesse both superior MS (2.4–2.8 T) and high thermostability with standing 450 °C annealing. Furthermore, by first-principles calculations, we reveal that the synergistic regulation on the thermostability is closely related to the solution heat tunability of Fe-N phases. The Fe/Cr/FeN:Co heterostructure may serve as a promising material for constructing high-efficient writing heads, permanent magnets, and other magnetic devices.

Tailoring the magnetic anisotropy of a ferromagnet film is the critical issue to construct high-efficient magnetic memory and logic devices. In this paper, we demonstrated a controllable magnetic anisotropy of Pt/Co/HfO2 multilayers by tuning the oxygen-dependent orbital occupancy at the Co/HfO2 interface. Driven by the large difference in formation enthalpy between HfO2 with CoO, an effective O2− migration occurred at the Co/HfO2 interface by thermal activation, which increased the electronic occupation on the Co 3dz2 orbit and facilitated the out-of-plane Co-O orbital hybridization. Therefore, the interfacial magnetic anisotropy energy was enhanced by two times, leading to a transition from in-plane to out-of-plane anisotropy. Conversely, the O2− migration was suppressed when HfO2 was replaced by ZnO with the formation enthalpy close to CoO, which makes the orbital tunability effect disappear and the magnetic anisotropy of film unchangeable. These findings are crucial for exploiting the magnetoionic control of interfacial magnetism and advancing the functionalized design of memorizers based on orbital engineering.

Pseudo spin valves (SVs) exhibiting perpendicular magnetic anisotropy were prepared by magnetron sputtering. Magnetization measurements of the Co/Pt multilayers were performed to select the reference and free layers. The selection criteria are square magnetic hysteresis loops, weaker current shunting effect, and proper coercivity. The optimal reference layer and free layer are Pt(5.0 nm)/[Co(0.4 nm)/Pt(0.6 nm)]3/Co(0.4 nm)/Cu(3.0 nm) and Cu(3.0 nm)/[Co(0.4 nm)/Pt(1.5 nm)]4, respectively. The resulting pseudo SV exhibits two well-separated hysteresis loops when the field is applied perpendicular to the film plane. The minor hysteresis loop corresponding to the free layer shifts toward negative direction of the magnetic field axis, indicating ferromagnetic interlayer exchange coupling between the two magnetic layers. The coupling also enhances the coercivity (H C) of both layers. The perpendicular giant magnetoresistance (GMR) of 2.7 % is achieved with current in plane measurement. The GMR first increases when Pt seed layer is thickened, reaches a maximum of 3.0 % at 4 nm and then decreases with the further increase of thickness. But thicker Cu spacer layer always lowers the GMR of the SV.

L1 0 -FePt based perpendicular exchange coupled composite (ECC) films with both weak FePt interparticle exchange coupling (IPEC) and strong hard/soft exchange coupling (HSEC) are virtually crucial to improve the signal-to-noise ratio and the writability of recording media concurrently. This article reports synthesis and magnetic property tunability of the L1 0 -FePt:Au/Fe ECC film with low IPEC between neighboring L1 0 -FePt particles and strong HSEC between the hard L1 0 -FePt:Au composite layer and the soft Fe layer. Moreover, the magnetic domain configuration study reveals the domain wall assisted magnetization reversal mechanism. The coupled Fe layer facilitates reverse nucleation and magnetization reversal in the L1 0 -FePt:Au composite layer, leading to remarkable reduce of the switching field while maintaining high thermal stability.

We investigated the current-induced magnetization switching in a perpendicular magnetized Pt/CoNiCo/Pt sandwich structure by spin-orbit torques under in-plane gradient current density. The gradient spin current density resulted from the spin Hall effect along the current direction was achieved by designing a bottom wedged Pt electrode. An in-plane effective field along the current direction is induced by the wedged Pt layer, which determines the direction of the current induced magnetization switching. The effective field increased with the slope of the wedged Pt, and is sufficient to induce deterministic switching of nearly 90% domains with the slope value of 0.21.

Here, DC power supplies were applied on as-deposited non-perpendicular FePt single films or perpendicular FePt/Au multilayer films to control momentum exchanges between rapid moving electrons and Fe or Pt atoms. Moreover, lattice defects in the films provide abundant diffusion pathways for atomic rearrangement. Through the current driven atomic motion and rearrangement, fast LOP and hard magnet properties were realized in the FePt alloy films without heat treatment. The electromigration effect appears to be general and is applicable for the ordering in other magnetic materials with a L1 0 structure.

A series of Cr/SmCo/Cr films with high Sm concentration (37.7at%) were prepared by magnetron sputtering. Effects of SmCo thickness, annealing temperature, and annealing time on magnetic properties and crystal structure were carefully studied. Results show that crystallization degree and phase transition in the films can be controlled by the SmCo thickness and optimized by properly increasing the annealing temperature and extending the annealing time. Finally, a SmCo film with high magnetic properties and low MEI was constructed.

Based on interfacial microstructure control of FePt/Au multilayer structure and surfactant Bi atoms, an FePtBi/Au nanocomposite film was designed to achieve good properties [low-temperature ordering, good perpendicular magnetic anisotropy (PMA), and no interparticle exchange coupling (IEC)] in this paper. The ordering process was promoted due to the increase of concentration of defects by adding appropriate surfactant Bi atoms. Thus, the ordering temperature of this film can be decreased from 500 to 450 °C. Meantime, the FePtBi/Au nanocomposite film maintains good PMA and low IEC with the texture manipulation of Au layers and control of total film thickness.

Cr/SmCo/Cr films with different SmCo thickness were deposited on glass substrates by magnetron sputtering, followed by an annealing process at 550 °C for 20 min. Experimental results showed that the SmCo film of 30 nm exhibited two-phase behavior in the demagnetization process, the obvious kink was observed near zero. For the SmCo film of 50 nm, the kink was invisible, and a single phase like behavior was obtained in the demagnetization process. The reversal behavior became consistent in the thicker films. Moreover, the coercivity reduced and the saturated magnetization increased obviously with the increasing thickness. X-ray diffraction results indicated that the average grain size of SmCo 5 in the thicker films were almost 30 nm, but the quantity of SmCo 5 grains increased with the increasing thickness, which enhanced the intergrain exchange coupling (IEC) of the SmCo 5 hard phases. The increase of IEC improved the magnetic properties of SmCo films with increasing thickness.

Ta/MgO/NiFe/MgO/Ta ultrathin films with and without intercalation of NiFe nanoparticles in MgO layers were prepared by magnetron sputtering, followed by a vacuum annealing process. The measured and calculated results show that the former has higher specular electron scattering (SES) parameter at MgO/NiFe interfaces, lower resistivity, and higher magnetoresistance (MR). The improved transport properties (TPs) are mainly attributed to the suppressed diffuse electron scattering by means of the introduction of NiFe nanoparticles.

High thermal stability and tunable magnetic exchange interaction (MEI) in SmCo materials have been the critical problem in applications to magnetic recording media and nanocomposite permanent magnets. We constructed SmCo films with a high thermal stability and tunable MEI by controlling the phase transformation through properly increasing the Sm concentration (20.5–37.7 at.%) and controlling the annealing process. Microstructure studies show that the SmCo5 phases ensure that the film has a high thermal stability. Moreover, we manipulated the MEI in the film with non-magnetic precipitated SmCo2 particles in the vicinity of SmCo5 particles. These results provide a novel way to tune the MEI in SmCo materials while maintaining a high thermal stability.

A systematic study of the Mn-site substitution by M = Al, Cr, Fe, Co, Ni, Cu, and Ga in polycrystalline La0.7Sr0.3Mn0.9M0.1O3 compounds has been carried out. It was deduced from the experimental data that the magnetic coupling between the M and Mn ions is antiferromagnetic for Cr3+ and Fe3+, and ferromagnetic for Co2+/3+, Ni2+, and Cu2+. The variation of the Curie temperature versus M was discussed in terms of the double-exchange (DE) interaction of Mn3+ O Mn4+ as well as the superexchange interactions between the M and Mn ions. It is found that the Mn-site substitution by various M could not enhance the MR response at a low magnetic field of 2 kO.

The microstructural, magnetic, and magnetotransport properties of polycrystalline samples with nominal composition of La0.7Sr0.3Mn1–xVx O3 (0 ≤ x ≤ 0.25) sintered in air have been investigated. It is found that V could not substitute for Mn to form La0.7Sr0.3Mn1–xVx O3. The samples contain several phases such as (La, Sr)Mn1–δO3, LaSr3V3O12, Mn3O4 etc. and constitute multi-phase composites. The Sr–V-rich phase form a liquid phase during sintering process and the sintering be long to liquid-phase sintering, which may effectively promote grain growth of (La, Sr)Mn1–δO3 phase. The Curie temperature TC and saturation magnetization of the composites decrease with increasing the V content x. The addition of V may effectively improve the low-field MR response at low temperatures due to the variation in the microstructure of the composites. The MR ratio at a low field of 2 kOe reaches 25% for the x = 0.15 sample at 84 K. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Polycrystalline samples with nominal composition of La 0.7 Ca 0.3 Mn 1− x V x O 3 (0⩽ x ⩽0.2) sintered in air were investigated by ac susceptibility, dc magnetization, magnetoresistance (MR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and differential thermal analysis (DTA) measurements. It is found that V could not substitute for Mn to form La 0.7 Ca 0.3 Mn 1− x V x O 3 phase when the samples are sintered in air. The obtained samples contain several phases such as (La, Ca)Mn 1− δ O 3 , LaCa 3 V 3 O 12 , Mn 3 O 4 phases, etc. and constitute multi-phase composites. The Curie temperature T C and spontaneous magnetization of the composites decrease, and the resistance of the composites increases as the V content increases. The addition of V may effectively improve the low-field MR response at low temperatures due to the variation in the microstructure of the composites.

Current induced magnetization switching by spin-orbit torques offers an energy-efficient means of writing information in heavy metal/ferromagnet (FM) multilayer systems. The relative contributions of field-like torques and damping-like torques to the magnetization switching induced by the electrical current are still under debate. Here, we describe a device based on a symmetric Pt/FM/Pt structure, in which we demonstrate a strong damping-like torque from the spin Hall effect and unmeasurable field-like torque from Rashba effect. The spin-orbit effective fields due to the spin Hall effect were investigated quantitatively and were found to be consistent with the switching effective fields after accounting for the switching current reduction due to thermal fluctuations from the current pulse. A non-linear dependence of deterministic switching of average Mz on the in-plane magnetic field was revealed, which could be explained and understood by micromagnetic simulation.

[Co/Ni] N and [Co/Pt] N multilayers are ideal perpendicular magnetic anisotropy materials due to their high spin polarization. There are strong perpendicular magnetic anisotropy(PMA) energy between Co and Ni or Pt layer, and if the energy is strong enough to overcome the demagnetizing effect the easy magnetization axis can be perpendicular to the film[1-3]. Perpendicularly magnetized spin valve structure can be prepared by these properties and it has significant implication in high density magnetoresistive random access memory(MRAM) and other aspects[4]. In this work, a perpendicularly magnetized spin valve structure was developed, consisted the ferromagnetic [Co/ Ni] and [Co/Pt] multilayers and separated by a Au spacer. The magnetoresistance(MR) of the samples with the thickness of Au and the layer repetition number of N was studied.

The oscillation of diffraction efficiency is observed in the nonvolatile holographic recording of lithium niobate crystals doped with iron and copper. The physics of oscillation in doubly doped lithium niobate crystals is studied by using Runge–Kutta methods, and the oscillation can be attributed to the redistribution of electrons in the deeper and shallower traps of the crystals in the initial phase of holographic recording. The effects of Fe concentration and intensity ratio of red beams to UV beam ( I R / I UV ) on the oscillation are investigated theoretically. The results show that with lower Fe concentration, the amplitude of oscillation is larger and with lower intensity ratio I R / I UV , the duration of the oscillation is longer.

Current-induced fast-ordering method (CIFOM) was designed to achieve an ordered L10 -FePt film with small grain size under low energy consumption by applying direct current (DC) in the FePt film. The grain size (~ 8 nm) of the L10-FePt film prepared by CIFOM method is about one-third of that produced by the post-annealing method (PAM). The fast ordering of the L10-FePt film by CIFOM is probably attributed to the momentum exchange between the FePt atoms and the conductive electrons. The short ordering time by CIFOM contributes to the smaller grain size of FePt film.

The fixing phase of the two-center holographic recording is not consistent with the mono-exponential formula, and the charge-transfer mechanism of the fixing phase is studied theoretically. The electron gratings of the shallower traps center have a great influence on the fixed space-charge-field, the stronger electrons grating of the shallower traps center would enhance the saturation space-charge-field of the deeper traps center in the fixing phase. The effects of the Fe concentration, Cu concentration and the oxidization-reduction state of the crystals on the fixed space-charge-field are investigated by using the Runge-Kutta method. The results show that the higher Fe concentration, the lower Cu concentration and the weakly oxidized crystal are available for enhancing the saturation space-charge-field of the deeper traps center.

A high-average-power and high-beam-quality diode-side-pumped solid-state laser was designed carefully for laser beam texture. By using of low concentration Nd:YAG crystals with thermally near-unstable resonator design and two-rod birefringence compensation technology, the 1064 nm cw output power of 400 W at pump power of 1170 W was achieved with the beam quality factor M 2 ~ 15, corresponding to an optical-to-optical conversion efficiency of 34.2%.

A co-folding-arm plane-plane symmetrical L-shaped Nd:YAG laser cavity is designed by carefully computer simulation, and continuous-wave yellow light at 589 nm is obtained with output power of 3.23 W.

This article reports property manipulations and related dynamical evolution in electromigration controlled FePt perpendicular films. Through altering voltage and treatment time of the power supply applied on the films, electronic momentum was fleetly controlled to manipulate the kinetic energy of Fe and Pt atoms based on momentum exchanges. The electromigration control behavior was proven to cause steerable ordering degree and grain growth in the films without thermal treatment. Processed FePt films with small grain size, high magnetocrystalline anisotropy, and controllable coercivity can be easily obtained. The results provide a novel method for tuning magnetic properties of other L10 structured films.