Metallo-organic Decomposition Research Articles

High-quality YIG films preparation by metallo-organic decomposition and their use to fabricate spintronics nanostructures by focused ion beam

High-quality YIG films preparation by metallo-organic decomposition and their use to fabricate spintronics nanostructures by focused ion beam

Structural, magnetic, magneto-dielectric and magneto-electric properties of (1-x) Ba0.85Ca0.15Ti0.90Zr0.10O3 – (x) CoFe2O4 lead-free multiferroic composites sintered at higher temperature

Here in this article synthesis of lead-free magnetoelectric composites (1-x) Ba0.85Ca0.15 Ti0.9Zr0.1)O3 - xCoFe2O3 (BCTZ-CFO, x = 0.4, 0.5, and 0.6) is reported. Structural, magnetic, dielectric, magnetodielectric and magnetoelectric properties of lead-free BCTZ-CFO composites sintered at higher sintering temperature have been systematically investigated. The piezoelectric (ferroelectric) phase has been synthesized using the sol–gel route, while Metallo-organic decomposition (MOD) route was employed to prepare piezomagnetic (ferrite) phase. The structural and microstructural properties were studied using X-Ray diffraction and Scanning electron Microscope respectively acknowledged the presence of two distinct phases as ferrite and ferroelectric in composite samples. The dense microstructure and larger average grain size were observed for samples with higher ferrite phase content. Long-range magnetic order was observed under magnetic study for all-composites. The magnetic properties enhanced for composites prepared with higher ferrite phase content. Dielectric properties were studied at room temperature and enhanced dielectric constant has been observed for samples with higher ferroelectric phase content, while minimum dielectric loss was observed for sample with 50/50 ferrite/ferroelectric phase composition. The magnetodielectric response has been also investigated for all ME composites. Leakage current characterization has been also discussed at and above the room temperature. The magneto-electric coupling response was measured of all composites. The higher value of magneto-electric coupling coefficient has been observed for 0.5BCTZ-0.5CFO composite due to maximum possible ferrite-ferroelectric hetero-structure phase contact area.

Highly smooth and conductive silver film with metallo-organic decomposition ink for all-solution-processed flexible organic thin-film transistors

A facile silver metallo-organic decomposition (MOD) ink and its two-step sintering process was developed to fabricate highly conductive and smooth silver film for the flexible organic electronics. Using simple and feasible two-step sintering processes and double-layer processes, the conductivity of silver film with the facile MOD ink was greatly improved from 2.85 × 103 S cm−1 to 1.50 × 105 S cm−1, indicating about 53 times increase and about 24% bulk silver conductivity, and the surface RMS roughness was about 6 nm by atomic force microscope, nearly identical to the thermal-evaporated silver film. The XRD showed that synthesized silver thin films were composed of pure silver and well crystallized to the face-centered cubic structure, similar to metallic silver. And the full XPS spectra showed the presence of the same elements and almost identical peaks of solution-processed silver, as compared to the thermal silver surface elemental data. Besides, the silver film also demonstrated great mechanical stability and adhesion on PET substrate. At last, using silver gate/source/drain electrodes generated from the MOD ink, the all-solution-processed organic thin-film transistors (OTFTs) were demonstrated. The optimized OTFTs exhibited a high field mobility of 0.36 cm2 V−1 s−1 with threshold voltage of 0.35 V and on/off current ratio of 1 × 105.

Surface, structural and cryogenic magnetic studies of Cu, Co substituted NiFe2O4 thin films grown on Si substrate

Silicon (Si) is the most commonly used substrate material for fabricating integrated circuit; Si has very little fatigue effect. In the present work we developed pure NiFe2O4 and Cu, Co substituted NiFe2O4 thin films on Si substrate by metallo-organic decomposition (MOD) method using spin coating technique. The prepared thin films were characterized by XRD and Raman spectrometer for structural and phase identification. The topography and grain distribution of the prepared samples were analyzed by atomic force microscope (AFM). Magnetic hysteresis loops were measured at 10 K and 300 K using Superconducting quantum interference device (SQUID). The magnetization and coercive field increased with Cu, Co substitution. Temperature dependent magnetization (M-T) was carried out by zero-field cooled (ZFC) and field – cooled (FC) method. ZFC measurements revels that blocking temperature of the thin films is above 350 K.

Structural and magnetic study of metallo-organic YIG powder using 2-ethylhexanoate carboxylate-based precursors

The crystallization and magnetic behavior of yttrium iron garnet (YIG) prepared by metallo-organic decomposition (MOD) method are discussed. The chemistry and physics related to synthesis of iron and yttrium carboxylates based on 2-ethylhexanoic acid (2EHA) are studied, since no literature was found which elucidates synthesis of metallo-organic precursor of YIG in spite of the literatures of doped YIG samples such as Bi-YIG. Typically, the metal carboxylates used in preparation of ceramic oxide materials are 2-ethylhexanoate (2EH) solvents. Herein, the synthesis, thermal behavior and solubility of yttrium and iron 2EH used in synthesis of YIG powder by MOD are reported. The crystallization and magnetic parameters, including saturation magnetization and coercivity of these samples, smoothly change as a function of the annealing temperature. It is observed that high sintering temperature of [Formula: see text] to [Formula: see text] promotes the diffraction peaks of YIG, therefore, we can conclude that the formation of YIG in MOD method increases the crystallization temperature. The maximum value of saturation magnetization and minimum value of coercivity and remanence are observed for the sample sintered at [Formula: see text] which are 13.7 emu/g, 10.38 Oe and 1.5 emu/g, respectively. This study cites the drawbacks in chemical synthesis of metallo-organic-based YIG production.

Regulating crystal structure and ferroelectricity in Sr doped HfO2 thin films fabricated by metallo-organic decomposition

HfO2 based binary ferroelectric oxides are promising candidate for nonvolatile memory devices due to their compatibility with the current Si-based technology. In this work, Sr doped HfO2 (Sr:HfO2) ferroelectric thin films with Sr concentration from 0% to 10 mol% were prepared on the platinum electrodes by metallo-organic decomposition (MOD). It was demonstrated that uniform Sr:HfO2 thin films with extremely low roughness can be achieved and crystallized by MOD under a 700 °C annealing process. A wake-up stage was believed more essential for the ferroelectricity of the MOD derived Sr:HfO2 thin film, since the remnant polarization of 13.3 µC/cm2 and high dielectric constant of 30 were obtained after 105 cycling tests. The transformation from monoclinic phase to cubic phase was observed with increasing the Sr concentration and the thickness of the films. X-ray photoelectron spectroscopy analysis confirmed the bonding type of O-Hf-O and O-Sr-O bonds in the film. The microscopic crystal structure of ferroelectric orthorhombic phase was observed by high resolution transmission electronic microscope. The intrinsic ferroelectricity of Sr:HfO2 film was demonstrated by the hysteresis polarization-voltage loops and distinct current peaks in the current-voltage curve. Stable domain structure and its switching dynamics were monitored by piezoresponse force microscopy, indicating the native polarization of Sr:HfO2. This work will provide a controllable routine to fabricate ferroelectric HfO2 based thin films using MOD method.

Filtration-induced production of conductive/robust Cu films on cellulose paper by low-temperature sintering in air.

Cellulose paper is an attractive substrate for paper electronics because of its advantages of flexibility, biodegradability, easy incorporation into composites, low cost and eco-friendliness. However, the micrometre-sized pores of cellulose paper make robust/conductive films difficult to deposit onto its surface from metal-nanoparticle-based inks. We developed a Cu-based composite ink to deposit conductive Cu films onto cellulose paper via low-temperature sintering in air. The Cu-based inks consisted of a metallo-organic decomposition ink and formic-acid-treated Cu flakes. The composite ink was heated in air at 100°C for only 15 s to give a conductive Cu film (7 × 10−5 Ω cm) on the cellulose paper. Filtration of the Cu-based composite ink accumulated Cu flakes on the paper, which enabled formation of a sintered Cu film with few defects. A strategy was developed to enhance the bending stability of the sintered Cu films on paper substrates using polyvinylpyrrolidone-modified Cu flakes and amine-modified paper. The resistance of the Cu films increased only 1.3-fold and 1.1-fold after 1000 bending cycles at bending radii of 5 mm and 15 mm, respectively. The results of this study provide an approach to increasing the bending stability of Cu films on cellulose paper.

Structural, multiferroic, dielectric and magnetoelectric properties of (1-x)Ba0.85Ca0.15Ti0.90Zr0.10O3-(x)CoFe2O4 lead-free composites

High performance lead-free multiferroic composites with strong magnetoelectric coupling effect are desired to replace lead-based ceramics in multifunctional device applications due to increasing environmental issues. We report crystal structure, ferroelectric, magnetic, dielectric and magnetoelectric properties of (1-x)Ba0.85Ca0.15Ti0.90Zr0.10O3-(x)CoFe2O4 (BCTZ-CFO) lead-free composites with x = 0.1, 0.3, 0.5, 0.7 and 0.9 synthesized by chemical solution method. BCTZ power was synthesized by sol-gel method while CFO was prepared by metallo-organic decomposition (MOD) method. The XRD results confirm successful formation of the BCTZ-CFO composites without presence of any impurity phase. At room temperature, the BCTZ-CFO composites show multiferroic behavior characterized by ferroelectric and ferromagnetic hysteresis curves. The composite having 10 wt% of CFO exhibited maximum polarization, remnant polarization and coercive field of Ps ∼ 5.1 µC/cm2, Pr ∼ 1.4 µC/cm2 and Ec ∼ 11.6 kV/cm respectively. The BCTZ-CFO composite with 90 wt% of CFO incorporation exhibits improved ferromagnetic properties with Ms ∼ 32 emu/g, Mr ∼ 11.7 emu/g and Hc ∼ 504 Oe. Mӧssbauer spectra analysis show two sets of six-line hyperfine patterns for BCTZ-CFO composites, indicating the presence of Fe3+ ions in both A and B sites. Increasing BCTZ content was found to decrease the hyperfine field strength at both sites and is consistent with the decreasing magnetic moment observed for the samples. The maximum dielectric constant value ε′ ∼ 678 is obtained at 1 MHz for composite with 10 wt% of CFO phase. The results indicate that the BCTZ-CFO composites are potential lead-free room temperature multiferroic systems.

Strain-induced nanostructure of Pb(Mg1/3Nb2/3)O3–PbTiO3 on SrTiO3 epitaxial thin films with low PbTiO3 concentration

The singularity of the structure in (1 − x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN–xPT) (x = 0–50 mol %) epitaxial thin films of 100 nm thickness was investigated from the viewpoint of the localized residual strain in the nanoscale. The films were deposited on SrTiO3 (STO) (001) single-crystal substrates by chemical solution deposition (CSD) using metallo-organic decomposition (MOD) solutions. X-ray and electron diffraction patterns revealed that PMN–xPT thin films included a single phase of the perovskite-type structure with the cube-on-cube orientation relationship between PMN–xPT and STO: (001)Film ∥ (001)Sub, [100]Film ∥ [100]Sub. X-ray reciprocal space maps showed an in-plane tensile strain in all the compositional ranges considered. Unit cells in the films were strained from the rhombohedral (pseudocubic) (R) phase to a lower symmetry crystal system, the monoclinic (MB) phase. The morphotropic phase boundary (MPB) that split the R and tetragonal (T) phases was observed at x = 30–35 for bulk crystals of PMN–xPT, whereas the strain suppressed the transformation from the R phase to the T phase in the films up to x = 50. High-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) analysis and its related local strain analysis revealed that all of the films have a bilayer morphology. The nanoscale strained layer formed only above the film/substrate semi-coherent interface. The misfit dislocations generated the localized and periodic strain fields deformed the unit cells between the dislocation cores from the R to an another type of the monoclinic (MA) phase. Thus, the singular and localized residual strains in the PMN–xPT/STO (001) epitaxial thin films affect the phase stability around the MPB composition and result in the MPB shift phenomena.

Multiferroic effects in MFe 2 O 4 /BaTiO 3 (M = Mn, Co, Ni, Zn) nanocomposites

An increasing demand in realizing ultra-fast, compact and ultra-low power spintronic devices has impelled the creation of novel multiferroic heterostructures which enable voltage control of magnetism and vice-versa. For this, we have reported multiferroic properties of M(=Mn, Co, Ni, Zn)Fe2O4/BaTiO3 (MFO/BTO) nanocomposite. The MFO/BTO thin films were prepared by metallo-organic decomposition method. The MFO/BTO nanocomposite stoichiometric ratio has been analyzed with X-ray fluorescence elemental analysis. X-ray diffraction reveals the formation of both spinel MFO and perovskite BTO phases with crystallite size lies in the range of 25–137 nm. The lattice strain observed in MFO/BTO nanocomposite is due to tetragonal distortion of BTO unit cell and lattice mismatch with ferrite MFe2O4. The crystallite size is also depicted with atomic force microscopy. The observed ferromagnetism of MFO/BTO nanocomposite is highly influenced by inversion degree of MFO ferrite and oxygen vacancies formation. All MFO/BTO nanocomposites have well saturated ferroelectric hysteresis polarization. This has been discussed based on lattice strain, leakage current and the degree of lattice mismatch. The chemical valence states of Fe and O and their influence on the magnetic and ferroelectric properties have been analyzed with X-ray photoelectron spectroscopy. The capacitance versus bias voltage characteristics under the influence of applied dc magnetic field indicates ferroelectric behavior and the presence of magneto-electric/dielectric effects. The dielectric permittivity reduces with applied dc magnetic field which is responsible for negative magnetodielectric effect. The higher longitudinal magnetoelectric coupling coefficient is obtained in M(=Co, Ni, Zn)FO/BTO nanocomposite which is correlated with piezoelectric coefficient, d33 value measurement.

Plasma-Induced Decomposition of Copper Complex Ink for the Formation of Highly Conductive Copper Tracks on Heat-Sensitive Substrates.

The use of Cu-formate-2-amino-2-methyl-1-propanol ink and low-pressure plasma for the formation of highly conductive patterns on heat sensitive plastic substrates was studied. It was found that plasma results in decomposition of copper complex to form metallic copper without heating at high temperatures. Ink composition and plasma parameters (predrying conditions, plasma treatment duration, gas type, and flow rate) were optimized to obtain uniform conductive metallic films. The morphology and electrical characteristics of these films were evaluated. Exposing the printed copper metallo-organic decomposition (MOD) ink to 160 W plasma for 8 min yielded resistivity as low as 7.3 ± 0.2 μΩ cm, which corresponds to 23% bulk copper conductivity. These results demonstrate the applicability of MOD inks and plasma treatment to obtain highly conductive printed patterns on low-cost plastic substrates and 3D printed polymers.

Investigation on multiferroic, optical and photoluminescence properties of CoFe2O4/(Pb1−xSrx)TiO3 nanostructured composite thin films

Multiferroic nanostructured composite thin films consisting of CoFe2O4 (CFO) and Pb1−xSrxTiO3 (PST; x = 0.1, 0.2, 0.3, 0.4 and 0.5) layers have been deposited on Pt/TiO2/SiO2/Si and quartz substrates by using metallo-organic decomposition process and spin coating. The effect of Sr content on the multiferroic and optical properties have been investigated. The phase purity such as spinel structure of CFO and perovskite structure of PST has been verified by X-ray diffraction. Cross-sectional scanning electron microscopy images revealed clear interface between CFO and PST layers without any noticeable diffusion. The multiferroic properties of CFO/PST composite films have been confirmed by magnetic and ferroelectric hysteresis loops with low leakage current density. The residual strain sensitivity of multiferroic and optical properties has been observed in the composite films. The decrease in saturation magnetization and saturation polarization with increase in Sr content has been observed which could be attributed to the decrease in residual strain of CFO/PST composite films. The magnetic phase transition temperature of the CFO/PST composite films is also reduced. The optical refractive index decreases with increase of amount of Sr content. The photoluminescence spectra of the CFO/PST composite films possess a blue shift which can be attributed to the Pb and oxygen vacancies as localized sensitizing centers. We show that the multiferroic and optical properties of the CFO/PST composite films are highly sensitive to the heterostructure strains which can be controlled by Sr content.

Structural and Magnetic Investigation of Cu, Co Substituted NiFe<sub>2</sub>O<sub>4</sub> Thin Films by Scanning Probe Microscopy (AFM, MFM)

In the present study we prepared NiFe2O4, Ni0.95Cu0.05Fe2O4 and Ni0.94Cu0.05Co0.01 Fe2O4 thin films by metallo-organic decomposition method (MOD) using spin coating technique. The samples were characterized by XRD. XRD patterns of thin films confirmed the formation of cubic spinel structure without any secondary phase. For microstructural analysis we characterized samples by Scanning Probe Microscope (SPM). From Atomic force microscopy (AFM), we analyzed surface morphology, calculated grain size, roughness and porosity. It has been found that grain size and roughness affected by Cu, Co substitution. After this we carried out magnetic force microscopy (MFM) on the samples. Effect of substitution on magnetic grains was observed from MFM.

Magneto-optical studies of BaFe_12O_19 films grown by metallo-organic decomposition

M-type barium hexagonal ferrites BaFe12O19 (BaM) films considered for new devices that operate in the 40-70 GHz range with small or zero applied magnetic fields were characterized by magneto-optical (MO) complex polar “Kerr” effect (PKE) spectroscopy, MO magnetometry, and spectral ellipsometry (SE). The textured polycrystalline films were grown on Pt(111)/TiO2 template on Si wafer using metallo-organic decomposition technique (MOD) followed by rapid thermal annealing. In the films grown in one, two and three MOD iterations, the thickness was evaluated by SE and transmission electron microscopy. The film thickness ranged from 30 nm to 50 nm per MOD iteration. The best films display out-of-plane effective magnetic anisotropy field of 13 kOe, high perpendicular remanent magnetization and ferromagnetic resonance linewidth of 340 Oe at 60 GHz. The coercivity deduced from the MO hysteresis loops ranged between 0.25 kOe and 0.52 kOe. The SE and PKE spectra were taken at photon energies from 0.7 eV to 6.4 eV and from 1.2 eV to 4.8 eV, respectively. The PKE spectra display the structure observed on BaM single crystal natural faces normal to the c-axis. They are consistent with magnetoplumbite structure, with high degree of grain c-axis ordering, absence of foreign phases and Fe valence-exchange mechanism. Single phase nature of the films was further confirmed by grazing incidence X-ray diffraction and 57Fe nuclear magnetic resonance at 4.2 K.

Multiferroic and magnetoelectric properties of CoFe2O4/Pb1−xSrxTiO3 composite films

To realize multiferroic and magnetoelectric properties, bi-layered nanocomposite films consisting of CoFe2O4 (CFO)/Pb1−xSrxTiO3 (PST) phases (x = 0.1, 0.2, and 0.3) have been deposited on Pt/TiO2/SiO2/Si substrate by using a metallo-organic decomposition process. Both the PST perovskite and the CFO spinel phases are confirmed from X-ray diffraction patterns and Raman spectra of the composite films. The composite films exhibit room temperature multiferroic properties. The values of saturation magnetization (Ms), remanent magnetization (Mr), and coercive field (Hc) of the composite films are in the range of 108–119 kA/m, 42–51 kA/m, and 44.5–64.1 kA/m, respectively. In addition, the saturation polarization (Ps), remanent polarization (Pr), and electrical coercive field (Ec) are observed in the range of 11.3–14.4 μC/cm2, 2.9–4.8 μC/cm2, and 56–59.5 kV/cm, respectively. The dielectric response in the presence of applied magnetic field, Hdc ∼ 238.6 kA/m shows a high magnetocapacitance value ∼385% at frequency 100 kHz for CFO/PST composite film with x = 0.1. The maximum magnetoelectric voltage co-efficient value, αE ∼ 380 kV/(m × T) has been achieved in the composite films with x = 0.1. The influence of elastic/and or interfacial strain on multiferroic magnetoelectric properties is evident from the results.

Effect of Ti concentration on the growth of chemically-ordered regions of Pb(Mg<sub>1/3</sub>Nb<sub>2/3</sub>)O<sub>3</sub>–PbTiO<sub>3</sub> epitaxial thin films

(1 − x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN–PT) (x = 0–1) epitaxial thin films with high crystallinity have been prepared by using metallo-organic decomposition (MOD) processes at a temperature half of the crystallization temperature of the corresponding bulk crystals. X-ray diffraction patterns show that Ti-poor and Ti-rich PMN–PT thin films have perovskite-type structure with a single phase of pseudocubic and/or tetragonal phase, respectively. The morphotropic phase boundary (MPB) is located around x = 0.6. Chemically-ordered regions (CORs), where Mg and Nb ions at B-sites show 1:1 ordered structure in the 〈111〉 directions, are clearly detected by using aberration-corrected high angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) images taken along the 〈110〉 directions, while it is difficult to analyze the detailed structure of the CORs by the electron or X-ray diffraction methods owing to the small volume. It showed that the density of COR rapidly decreases with increasing the Ti concentration, keeping the size of each COR, which infers that the COR may vanish at the Ti composition less than MPB. STEM analysis around the film/substrate interface shows the elastic interaction between CORs and local strain fields would be weak.

Investigation on impedance response, magnetic and ferroelectric properties of 0.20(Co1−xZnxFe2−yMnyO4)–0.80(Pb0.70Ca0.30TiO3) magnetoelectric composites

In the present work, we report on structural, dielectric, multiferroic, magnetoelectric properties and impedance spectroscopic studies of 0.20(Co1−xZnxFe2−yMnyO4)–0.80(Pb0.70Ca0.30TiO3) (x = 0.4, y = 0; x = 0, y = 0.2 and x = 0.4, y = 0.2) composites. The composites were prepared by metallo-organic decomposition (MOD) route. The coexistence of a cubic spinel phase and a tetragonal phase in the composites is confirmed by the X-ray diffraction measurement. Scanning electron micrographs show well distributed ferrite and ferroelectric phases in the composites. The dielectric properties of the composites have been studied in a wide range of frequency at different temperatures. The temperature dependent dielectric properties of the composites reveal that the ferroelectric–paraelectric transition temperature lies in the range of 499–546 °C. The impedance spectroscopic measurements of the composites indicate non-Debye type dielectric relaxation. The grain and grain boundary contributions in the composites have been separated using impedance spectroscopy analysis. The magnetization hysteresis (M−H) loop of the composites shows ferrimagnetic behavior with saturation magnetization values Ms ∼12–13.4 emu/g and coercive field Hc ∼71–273.5 Oe. The Curie temperature of the composites as determined from the inverse susceptibility vs. temperature curves is in the range of 297–480 °C. All the composites exhibit typical ferroelectric hysteresis loops indicating the presence of spontaneous polarization. A maximum value of magnetoelectric coupling co-efficient α ∼17.4 mV/cm Oe has been observed for the composite with x = 0.4 and y = 0.

Study of structure of the TiO2–MoO3 bilayer films by Raman spectroscopy

In this work, TiO2–MoO3 films were easily prepared by dip-coating technique and metallo-organic decomposition process (MOD). Raman analyses indicate the formation of TiO2 in anatase phase and orthorhombic phase of α-MoO3. It was observed that the Raman bands intensities attributed to TiO2 and MoO3 oxides were dependent on the number of decomposition–deposition cycles (DDC). The different number of DDC generates films with different thicknesses and the Raman signal was sensitive to this variation. Raman analyses provided qualitative information about the bilayer structure of the bi-component TiO2–MoO3 films, which was confirmed by scanning electron microscopy. In this direction, the dip-coating technique and MOD process can be an efficient strategy to facile preparation of many samples to be used in applications.

Room temperature ferromagnetism and photoluminescence of nanocrystalline Zn1 − xCoxO thin films prepared by sol–gel MOD

Zn1 − xCoxO (ZC) [x = 0, 1, 3, 5, 7 and 9 mol%] thin films were prepared by sol–gel combined metallo-organic decomposition method. The films were deposited on the Si substrate with spin-coating technique and annealed at 600 °C for 3 h. X-ray diffraction pattern shows the formation hexagonal wurtzite phase and distortion (c/a) decreases with increasing Co concentration in ZnO. The average grain size is measured using Scherer relation. Atomic force microscopy is used to confirm the formation of nanograins resulted by the use of polyethylene glycol as surfactant. The photoluminescence was recorded by using He-Cd laser of excitation wavelength 325 nm in wavelength region of 350–650 nm which exhibits some influence of Co doping on the multiplication of defects such as O vacancies, Zn interstitials and grain boundary defects. All thin films show room temperature ferromagnetism except pure ZnO which is diamagnetic and 9 mol% of Co shows paramagnetism. This behaviour is interpreted as due to fluctuations in the magnetic ordering, depending on grain size and site location in grain boundaries or oxygen vacancies.

Multiferroic and magnetoelectric properties of nanostructured BaFe0.01Ti0.99O3 thin films obtained under polyethylene glycol conditions

Multiferroic BaFe0.01Ti0.99O3 (BFT) thin films were prepared by sol–gel combined metallo-organic decomposition method using spin-coating technique with polyethylene glycol (PEG) conditions [BFT coating solution was prepared by adding PEG (in volume) 3% (BFT3) and 5% (BFT5)]. X-ray diffraction confirms the formation of polycrystalline BFT of tetragonal phase. Atomic force and scanning electron microscopy shows nanoparticles in BFT3 and nanorods in BFT5 sample. The coexistence of ferromagnetism and ferroelectricity show more enhancement in case of BFT nanorods than nanoparticles. The observed ferromagnetism depends upon the oxygen vacancy and ferroelectric polarization on nanostructures, tetragonal phase and epitaxial strain. The magnetoelectric coefficient as the function of applied dc magnetizing field under ac magnetic field 10Oe and frequency 847Hz is measured.