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Lead free calcium and zirconium co-doped barium titanate (Ba0.85Ca0.15Zr0.1Ti0.9)O3 (BCZT) ceramic has been prepared by conventional sol gel method. 50Ba0.7Ca0.3TiO3 –50BaZr0.2Ti0.8O3 [BCT-BZT] composite sample was prepared by mixing BCT and BZT powders in required stoichiometric concentration. The structural and micro structural analysis has been carried out by X-ray Diffraction (XRD) and scanning electron microscopy (SEM) images. Dielectric studies have been performed at room temperature and with temperature. Ferroelectric to paraelectric phase transitions has been observed in both ceramics. Higher values of dielectric parameters are obtained for co-doped BCZT as compared to its composite BCT-BZT. Further under the electric study, conduction mechanism for both ceramic study at room temperature and at different temperature. Activation energy is also calculated for both ceramics. [ABSTRACT FROM AUTHOR]

In the present work pure cobalt titanate powder was prepared using sol-gel technique by using cobalt acetate (C4H6CoO4.4H2O) and tetra-n-butyl titanate (C16H36OTi) as starting materials. The powder was annealed at 550℃and 750℃ for 5 hours. Structural properties were studied by X-ray diffraction (XRD). The XRD pattern of samples confirmed the rhombohedral structure formation of CoTiO3 without any secondary phase at 750℃. To see the morphology, the sample had been analysed by field emission scanning electron microscope (FE-SEM). Magnetic studies were carried out by Vibrating Sample Magnetometer (VSM). [ABSTRACT FROM AUTHOR]

Nickel Oxide (NiO) has been synthesized by the solution combustion technique. Ni-NiO composite ceramic was prepared and annealed at 600° C and 1000° C for 2 hours. Structural, electrical, dielectric and magnetic properties were analysed which depend upon the synthesis method. Structural properties were examined by X-Ray Diffractometer (XRD), which confirmed the purity and f.c.c. phase of Ni and Ni-NiO composite. XRD data reveals the decreases in crystallite size and increase in full width half maximum (FWHM) as the annealing temperature increases. Electrical conductivity is found to decrease from 10−2 to 10−6 (Ω−1cm−1) for Ni and Ni-NiOafter annealingtill 1000° C respectively. Dielectric constant for pure Ni is observed to be 3986 and decreased from 313.72 to 303.72 when the annealing temperature of Ni-NiO composite is increased from 600° to 1000°. High value of coercive field (54.31Oe) andremanent magnetization (1.18 emu/g) is found for Ni-NiO composite annealed at 1000° C. It is observed that better magnetic properties are achievedat higher annealing temperature for Ni-NiO composite ceramic. [ABSTRACT FROM AUTHOR]

Na0.5Bi0.5TiO3 (NBT) and CoFe2O4 (CFO) powders were synthesized by conventional sol-gel and metallo – organic chemical solution methods respectively. The lead free 65NBT-35CFO multiferroic particulate composite was prepared by mixing NBT and CFO powders in required stoichiometric concentration. The presence of ferroelectric (NBT) and ferrite (CFO) phases had been confirmed by X-ray diffraction analysis (XRD) and field emission scanning electron microscopy (FESEM) micrographs. Ferroelectric and ferromagnetic behaviors were also confirmed by polarization vs. electric field (P-E) and M-H hysteresis loops respectively. The current-voltage (I-V) characteristics were studied by using Keithley 2611 Source Meter. [ABSTRACT FROM AUTHOR]

The lead-free BaTiO3 (BT) thin film solution has been prepared by sol-gel method. The prepared solution spin coated on Pt/TiO2/SiO2/ Si substrate. The fabricated thin film was analyzed by XRD and Raman spectrometer for structural conformation. Uniformity of thin film was examined by Atomic force microscope (AFM). Thickness of the film was measured by cross sectional FESEM. Activation energies for both positive and negative biasing have been calculated from temperature dependent leakage current density as a function of electric field. For ferroelectric memory devices such as FRAM the hysteresis loop plays important role. Electric filed dependent polarization of BT thin film measured at different switching voltages. With increasing voltage maximum polarization increases. [ABSTRACT FROM AUTHOR]

Lead free Ba0.85Ca0.15Zr0.1Ti0.9O3(BCTZ) ceramic has been synthesized by sol-gel method. Properties of material are studied at different sintering temperatures for 5 hours. Structural and microstructural properties are analyzed by using X-ray diffractrometer (XRD) and scanning electron microscopy (SEM) at annealing temperature of 850°C and 1050°C XRD pattern confirm the perovskite structure of the material without any unwanted phases crystalinity increased with increase of sintering temperature so as roughness and porosity is decreased as shown by SEM micrographs. There is large improvement in density with rise of sintering temperature which also leads to drastic change in ferroelectric and dielectric properties. [ABSTRACT FROM AUTHOR]

Ba0.7Sr0.3(ZrxTi1-x)O3(BSZT, x=0,0.05,0.10,0.15,0.20) thin films were prepared by using sol gel method. Structural and microstructural properties were studied by using XRD, Raman Spectroscopy and atomic force microscopy (AFM) respectively. XRD and Raman Spectroscopy show the presence of tetragonal phase in multilayer BSZT thin film. The experimental results demonstrate that structural and microstructural properties of BSZT thin film were significantly dependent on variation of Zr content. [ABSTRACT FROM AUTHOR]

Multiferroic 2-2 type layered NFO/ (Pb0.50Sr0.50) TiO3 composite thin film on Pt/TiO2/Si substrate was prepared by novel metallo-Organic process using spin coating technique. The structural and surface morphology were confirmed by X-Ray diffraction (XRD) atomic force microscope (AFM). Significantly improved ferroelectric properties (Ps ∼ 8.69, Pr ∼ 3.19 μC/cm2 and Ec ∼ 419kV/cm) and magnetic properties (Ms), (Mr) and (Hc) is (104emu/cc, 0.8emu/cc and 25Oe.) were observed at room temperature. Our observation provides an effective way to manipulate the conduction behavior to understand the leakage current density of multiferroic composites film at the interface. Poole-Frankel tunneling conduction mechanism dominates the leakage current of films in the relatively high electric filed. [ABSTRACT FROM AUTHOR]

In the present study, nanoparticles of Fe doped zinc oxide (ZnO) [Zn1-xFexO where x=0.0, 0.01, 0.02, 0.03 and 0.05] were prepared by cost effective solution combustion method. The powder X-ray diffractometry confirms the formation of single phase wurtzite structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to investigate the micrsostructure of Fe-doped ZnO nanoparticles. The DC electrical conductivity was found to increase with temperature and measurement was carried out in the temperature range of 300- 473K. DC electrical conductivity increases with temperature and decreases with Fe doping concentration. [ABSTRACT FROM AUTHOR]

In the present work we prepared NCCFO thin films by metallo-organic decomposition (MOD) technique and studied the effect of different annealing temperature on structural and magnetic properties. The prepared thin film samples are annealed at four different temperatures (550°C, 650°C, 750°C, 850°C) for two hours. The XRD results confirmed the cubic spinel structure at different temperature with the sharpening of (311) peaks. The crystallite size was found to increase with annealing temperature and was further confirmed from AFM images. All samples show distinct hysteresis curves and improved ferromagnetic properties. The saturation magnetization increases with increase in annealing temperatures, while coercivity shows anomalous behavior which could be due to transformation from single to multi domain system. The ferrite thin films with distinct magnetic properties can find applications in many technological advanced nano devices. [ABSTRACT FROM AUTHOR]

In this work the effect of Ca doping on the structural and electrical properties of BaTiO3 thin films prepared by sol- gel method was investigated. The XRD patterns revealed the perovskite structure of BCT thin film shows tetragonality decreases with increase of Ca concentration at Ba-site. AFM images show dense, homogeneous and smooth micrograph of these thin films. The dielectric measurements of thin films show that dielectric constant decreases with Ca substitution. Polarization study shows the ferroelectric character of BCT thin films which decreases with increase in the concentration of Ca content on barium titanate. [ABSTRACT FROM AUTHOR]

Pb0.90Sr0.10TiO3-CoFe2O4(PST10-CFO) nanostructured bilayered thin film were grown on Si (100) substrate by using metallo-organic decomposition chemical route and spin coating technique. Results show that PST (pervoskite structure) and CFO (spinel) phase coexist in the bilayered thin films, annealed at 650°C for 2hr and no obvious impurity phase can be detected. The structural, surface morphology and micro structural properties were confirmed by X-Ray diffraction (XRD), atomic force microscope (AFM) respectively. Excellent ferroelectric behavior at different voltage was observed, with two platinum electrodes only at surface of the bilayer thin film. A room temperature ferromagnetic behavior was observed in the bilayered Pb0.90Sr0.10TiO3-CoFe2O4 nanostructured thin film. The saturation magnetization and variation in coercivity value of the bilayer thin film is lower than that of the pure CFO film in the presence of non ferromagnetic PST layer which is the attributed that the significant coupling between the two phases. [ABSTRACT FROM AUTHOR]

Lead free Na0.5Bi0.5TiO3 (NBT) was synthesized by conventional sol-gel method and CoFe2O4 (CFO) was prepared by metallo - organic decomposition (MOD) procedure. (65)Na0.5Bi0.5TiO3-(35)CoFe2O4 (65NBT-35CFO) multiferroic composite ceramic was prepared by mixing of NBT and CFO powder in their respective stoichiometric concentration. Structural properties were investigated by using X-ray diffractometer (XRD). The XRD patterns of NBT and CFO revealed the formation of rhombohedral and cubic structures respectively in there samples. In case of composite sample the presence of both phases was confirmed. The structural properties were also studied by Fourier transformation infrared spectroscopy (FTIR), which confirmed the presence of bands corresponding to the composite. The leakage current characteristic of the composite has been also investigated. [ABSTRACT FROM AUTHOR]

Lead free (Na0.5Bi0.5) 0.99La0.01Ti0.988 Fe0.012O3 (NBLTF) system has been synthesized by sol gel method without and with 2 mol% excess of Na and Bi. X-ray diffraction patterns of NBLTF samples confirm perovskite structure having rhombohedral R3c phase symmetry. Metal oxide band observed at ~ 629 cm-1 wavnumber in FTIR spectra also confirm formation of perovskite phase in samples. Microstructural analysis exhibits dense crystal growth having better grains connectivity for NBLTF sample with 2 mol% excess Na/Bi which is supported by room temperature DC resistivity measurements. Dense crystal growth and low leakage current with 2 mol% excess Na/Bi is reported to improve multiferroic properties of NBLTF sample and provides new insight to explore single phase lead free multiferroic system. [ABSTRACT FROM AUTHOR]

In the present work we prepared NiFe2O4, Ni0.95Cu0.05Fe2O4 and Ni0.94Cu0.05Co0.01 Fe2O4 thin films by metalloorganic decomposition method (MOD) using spin coating technique. The thin films were analyzed by X- ray diffractometer (XRD) and Atomic force microscope (AFM) for structural studies. The XRD patterns confirmed the ferrite phase of thin films. From AFM, we analyzed surface morphology, calculated grain size (GS) and root mean square roughness (RMSR). Room temperature magnetic properties were investigated by vibrating sample magnetometer (VSM). [ABSTRACT FROM AUTHOR]

Multiferroic 2-2 type bi-layered NFO/ (Pb0.80Sr0.20) TiO3 composite thin film on Pt/TiO2/Si substrate was prepared by novel metallo-Organic process using spin coating technique. The structural and surface morphology were confirmed by X-Ray diffraction (XRD) atomic force microscope (AFM). Significantly improved ferroelectric properties (Ps ~ 17.25, Pr ~8.02 µC/cm² and Ec ~ 404kV/cm) and magnetic properties (Ms ~ 117emu/cc, Mr ~ 0.83emu/cc and Hc ~ 20Oe) were observed at room temperature. The leakage current densities in NFO/PST composites film have been studied. Poole-Frankel bulk limited conduction mechanism dominates of film at relatively high electric filed. [ABSTRACT FROM AUTHOR]

This paper reports on the synthesis of Co doped Zn1-xCoxO (x= 0.0, 0.01, 0.02, 0.03 and 0.05) nanoparticles by solution combustion method using urea as a fuel. The Structural and dielectric properties of the samples were studied. Crystallite sizes were obtained from X-ray diffraction (XRD) patterns whose values decreased with increase in Co concentration. The XRD study reveals that Co2+ ions substitute the Zn2+ ion without changing the wurtzite structure of pristine ZnO up to Co concentrations of 5%. The dielectric constants, dielectric loss (tanδ) and ac conductivity (σac) were studied as the function of frequency and composition, which have been explained by Maxwell-Wagner type interfacial polarization and discussed Koops phenomenological theory. [ABSTRACT FROM AUTHOR]

Lead free (Na0.5Bi0.5)1-xLaxTi0.988Fe0.012O3 ceramic having compositions (x=0, 0.01, 0.03, 0.05) has been prepared by sol gel method using citric acid. Structural analysis has been done by X-ray diffraction and FTIR measurements. XRD patterns have been confirmed perovskite structure for all samples. FTIR absorption band at around ~630 cm-1 is observed for all samples which confirm perovskite phase formation in samples. With increasing La concentration, shifting in XRD peaks and FTIR absorption bands is observed which suggests incorporation of La on Asite in prepared (Na0.5Bi0.5)1-xLaxTi0.988Fe0.012O3 samples. Effect of La substitution on Ferroelectric (Polarization vs. Electric field) and Magnetic (Magnetization vs. Magnetic field) properties have been studied at room temperature. All samples exhibit weak ferromagnetic order and also possess ferroelectric behavior which provides new insight to lead free single phase multiferroic materials. [ABSTRACT FROM AUTHOR]

In the present work, we prepared Ba0.7Sr0.3TiO3 and Mn (2 and 3 at % on Ti site) doped Ba0.7Sr0.3TiO3 ceramic by sol- gel method. The samples were characterized by X-ray diffraction (XRD). The XRD patterns reveled that Mn ions did not change the perovskite structure of BST (70/30). The dielectric measurements proved that dielectric constant decreased with Mn doping. The dc resistivity was studied by using I-V measurements. The dc resistivity of the BST increased with Mn doping, which suppressed the leakage current. [ABSTRACT FROM AUTHOR]

(Pb0.60Sr0.40) TiO3-CFO composite thin films were grown on Pt/TiO2/Si substrate by novel metallo-Organic process using spin coating technique. The structural, surface morphology and micro structural properties were confirmed by X-Ray diffraction (XRD), Raman spectroscopy, atomic force microscope (AFM) and TEM respectively. The lattice constant of the composite thin film crystallized in the pervoskite and spinel phase was 3.9531 and 8.571 Å. Excellent ferroelectric behavior at 10V was observed, a room temperature magnetic hysteresis shows good results. The saturation magnetization value of the bilayer thin film is lower than that of the pure CFO film which is may be attributed to presence of non ferromagnetic PST layer A high initial behavior of dynamic ME response coefficient for the film was observed. The ME effect of the film strongly depends on the magnetic bias. [ABSTRACT FROM AUTHOR]