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1.
2 mol% Mn doped Ba(Zr0.2Ti0.8)O3 (Mn-BZT) thin films were prepared by pulsed laser deposition (PLD) on single crystal oxide substrates LaAlO3(001) and MgO(001), with conductive oxide bottom electrodes LaNiO3 and SrRuO3, respectively. Both the Mn-BZT films and the bottom electrode films could be c-axial oriented with a cube-on-cube arrangement on the corresponding substrates. The dielectric properties measured with parallel
plate capacitor configurations of Au/Mn-BZT/LNO and Au/Mn-BZT/SRO revealed that the Mn-BZT film on LNO bottom electrode exhibited
comparatively higher dielectric constant, larger dielectric tunability and lower dielectric loss than that on SRO. It could
be mainly attributed to the better epitaxial growth characteristics and mismatch stress of Mn-BZT thin film on LNO, as well
as less misfit dislocation and the better morphology of LNO bottom electrode. 相似文献
2.
We report on the epitaxial growth of SrRuO3 (SRO) thin films on Pt (111)/γ-Al2O3 (111) nSi (111) substrates. The grown thin films are crystalline and epitaxial as suggested by RHEED and XRD experiments. With the use of γ-Al2O3 (001)/nSi (001) and γ-Al2O3 (111)/nSi (111) substrates, crystalline but not epitaxial films have grown successfully. This result implies that lattice mismatch between nSi and SRO prevents the epitaxial growth of SRO film directly on nSi. However, the buffer Pt (111) layer mitigates lattice mismatch that provides to grow epitaxial film on nSi of quality. Morphological study shows a good surface with moderate roughness. Film grown at 700°C is smoother than the film grown at 750°C, but the variation of temperature does not affect significantly on the epitaxial nature of the films. 相似文献
3.
Zhijun Ma Tianjin Zhang Miao He Ruikun Pan Kai Fu Jingyang Wang 《Journal of Materials Science: Materials in Electronics》2011,22(1):35-39
Ba0.7Sr0.3TiO3 (BST) thin films were deposited on Pt and SrRuO3(SRO)/Pt hybrid bottom electrodes by radio frequency magnetron sputtering. X-ray analysis indicated that both films were polycrystalline.
Dielectric measurements showed that the films on SRO/Pt hybrid bottom electrode had lower dielectric constant and loss than
the films on single Pt and the dielectric properties were frequency-independent. The leakage current density of Ba0.7Sr0.3TiO3 thin films on hybrid bottom electrode was also lower. Leakage mechanism investigations showed that the contact between the
electrode-film interfaces of thin films on SRO/Pt hybrid bottom electrode was ohmic. Based on the results, the effects of
SRO/Pt hybrid bottom electrode on the crystallization and electrical properties of BST thin films were discussed. 相似文献
4.
W. F. Qin J. Xiong J. Zhu J. L. Tang W. J. Jie X. H. Wei Y. Zhang Y. R. Li 《Journal of Materials Science: Materials in Electronics》2007,18(9):973-976
Epitaxial Ba0.6Sr0.4TiO3 (BST)/LaNiO3 (LNO) heterostructures were fabricated on LAO (100) substrates using pulsed laser deposition
(PLD). Their structural properties were investigated by X-ray diffraction (XRD). The θ–2θ scans showed single crystalline
BST and LNO layers with a (100) orientations perpendicular to the substrate plane. Phi scans (ϕ) on the (220) plane of BST
layer indicated that the films have two in-plane orientations with respect to the substrate. The atomic force microscope (AFM)
surface morphologies showed a smooth and crack-free surface with the average grain size of 55 nm and the root-mean-square
(RMS) of 4.53 nm for BST films. Capacitance–voltage curves are measured. From the capacitance, a dielectric constant of 762,
tunabilty of 82.81% and loss tangent of 0.032 are obtained. The current–voltage curve shows that the leakage current is 2.41 × 10−7 A/cm2 under an applied voltage of 2 V. 相似文献
5.
W. F. Qin J. Zhu J. Xiong J. L. Tang W. J. Jie X. H. Wei Y. Zhang Y. R. Li 《Journal of Materials Science: Materials in Electronics》2007,18(12):1217-1220
Ba0.6Sr0.4TiO3 (BST) and 1.5 at% Y-doped Ba0.6Sr0.4TiO3 (Y-BST) thin films have been deposited on single-crystal (100) oriented LaAlO3 substrates using pulsed-laser deposition technique (PLD), respectively. X-ray diffraction (XRD) scanning revealed that the
two kinds of films could be epitaxially grown in pure single-oriented perovskite phases, but Y-BST thin films showed an enhanced
crystallization effect. The dielectric properties of the pure and Y-BST thin films were measured at 10 kHz and 300 K with
a parallel-plate capacitor configuration. The results revealed that the addition of Y as an acceptor doping is very effective
to increase dielectric tunability, and to reduce leakage current of BST thin films. The figure-of-merit (FOM) factor value
increases from 17.32 for BST to 25.84 for Y-BST under an applied electric field of 300 kV/cm. The leakage current density
of the BST thin films at a negative bias field of 300 kV/cm decreases from 2.45 × 10−4 A/cm2 to 1.55 × 10−6 A/cm2 by Y doping. The obtained results indicated that the Y-doped BST thin film is a promising candidate material for tunable
microwave devices. 相似文献
6.
CaCu3Ti4O12 (CCTO) thin film was successfully deposited on boron doped silica substrate by chemical solution deposition and rapid thermal
processing. The phase and microstructure of the deposited films were studied as a function of sintering temperature, employing
X-ray diffractometry and scanning electron microscopy. Dielectric properties of the films were measured at room temperature
using impedance spectroscopy. Polycrystalline pure phase CCTO thin films with (220) preferential orientation was obtained
at a sintering temperature of 750°C. There was a bimodal size distribution of grains. The dielectric constant and loss factor
at 1 kHz obtained for a film sintered at 750°C was k ∼ 2000 and tan δ ∼ 0.05. 相似文献
7.
Hwisim Hwang Yasutomo Uetsuji Tsutao Katayama Eiji Nakamachi 《Journal of Materials Science》2011,46(5):1380-1387
A three-scale analysis of crystal growth process is newly proposed based on the first-principles calculation and on the finite
element analysis in order to generate a new biocompatible piezoelectric thin film. Crystal growth process of lead-free BaTiO3 thin films was designed and experimentally generated on SrTiO3(100), (110), (111), and MgO(100) substrates using the radio-frequency magnetron sputtering method. Crystal structures of
BaTiO3 were measured by X-ray diffraction (XRD) θ/2θ scan. We used Pt for the electrode and measured piezoelectric strain constants d
33 using the ferroelectric measurement system. As a result, analytical crystal orientation fractions on SrTiO3(110) and (111) substrates had good quantitative agreement with experimental ones, and ones on SrTiO3(100) and MgO(100) substrates corresponded with these experimental crystal structures. Furthermore, analytically determined
piezoelectric strain constants d
33 qualitatively showed a good agreement with experimental ones. Especially, for SrTiO3(100) and MgO(100) substrates, the differences of d
33 depending on orientation fractions were analyzed by the three-scale simulation accurately. Consequently, it is confirmed
that the three-scale analysis is a useful simulation tool to design new biocompatible piezoelectric thin films. 相似文献
8.
Sn0.2Bi1.8Te3 thin films were grown using the thermal evaporation technique on a (001) face of NaCl crystal as a substrate at room temperature.
The optical absorption was measured in the wave number range 500–4000 cm−1. From the optical absorption data the band gap was evaluated and studied as a function of film thickness and deposition temperature.
The data indicate absorption through direct interband transition with a band gap of around 0.216 eV. The detailed results
are reported here. 相似文献
9.
Ken Nishida Takashi Yamamoto Minoru Osada Osami Sakata Shigeru Kimura Keisuke Saito Masamichi Nishide Takashi Katoda Shintaro Yokoyama Hiroshi Funakubo 《Journal of Materials Science》2009,44(19):5339-5344
Orientation controlled, micron-sized dot-patterned PZT films were grown by metal organic chemical vapor phase deposition (MOCVD),
and their crystal structure was evaluated. A micron-size dot-patterned SrRuO3 (SRO) buffer layer was initially prepared by MOCVD through a metal mask on the (111) Pt/Ti/SiO2/Si substrate. Then, a PZT film was deposited over the entire substrate. Micron-beam X-ray diffraction and Raman spectroscopy
indicated that (111)-orientated PZT was prepared on the SRO covered area, while the (100)/(001)-orientated one was directly
grown on Pt-covered substrates. The PZT film grown on SRO was thinner than that on the Pt-covered substrate. The estimated
ferroelectric property on the center of the dot pattern was larger than that at the circumference by Raman spectroscopy because
the strain is accelerated at the center of the dot. 相似文献
10.
Xiong Zhang Hongjia Song Congbing Tan Shengsheng Yang Yuxiong Xue Jinbin Wang Xiangli Zhong 《Journal of Materials Science》2017,52(24):13879-13885
In this paper, the epitaxial hexagonal LuFeO3 (h-LuFeO3) thin films with c-axis-oriented single phase, smooth surface were grown on YSZ (111) substrates by pulsed laser deposition method. Furthermore, a structural distortion of increased lattice constant of c is found in the epitaxial h-LuFeO3 thin films. Moreover, the epitaxial h-LuFeO3 thin films show room-temperature ferromagnetism. The coercive field and remnant magnetization of the epitaxial h-LuFeO3 thin film decrease with the increase in the test temperature from 50 to 300 K. The study would be of benefit to the room-temperature single-phase multiferroic materials. 相似文献
11.
We report on the epitaxial growth of SrRuO3 (SRO) thin films on Pt (111)/γ-Al2O3 (111) nSi (111) substrates. The grown thin films are crystalline and epitaxial as suggested by RHEED and XRD experiments.
With the use of γ-Al2O3 (001)/nSi (001) and γ-Al2O3 (111)/nSi (111) substrates, crystalline but not epitaxial films have grown successfully. This result implies that lattice
mismatch between nSi and SRO prevents the epitaxial growth of SRO film directly on nSi. However, the buffer Pt (111) layer
mitigates lattice mismatch that provides to grow epitaxial film on nSi of quality. Morphological study shows a good surface
with moderate roughness. Film grown at 700°C is smoother than the film grown at 750°C, but the variation of temperature does
not affect significantly on the epitaxial nature of the films. 相似文献
12.
Li Jia Yu Jun Wang Yunbo Peng Gang Li Jianjun 《Journal of Materials Science: Materials in Electronics》2010,21(2):137-140
Bi3.15Nd0.85Ti3O12 (BNT) thin film with a thin LaNiO3 film as buffer layer was fabricated by sol–gel method on Pt/TiO2/SiO2/Si substrate. The BNT thin films have a perovskite phase with a dense microstructure. The P
r and V
c value are 25.5 μc/cm2 and 3.7 V, respectively under the applied voltage of 15 V. After the switching of 2 × 109 cycles, the P
r value decreases to 86% of its pre-fatigue value. The leakage current density of the BNT thin films with LaNiO3 buffer layer were generally in the order of 10−8 to 10−6 A/cm2. The fatigue and leakage current properties were improved dramatically compared with the BNT film without a LaNiO3 buffer layer that we prepared before. The measured residual stress was tensile stress and its value was 176 MPa. 相似文献
13.
We have studied the structure, electric resistance, and magnetoresistance of 30-nm-thick (110)La0.67Ca0.33MnO3 (LCMO) films grown by laser deposition on (001)-oriented LaAlO3 substrates. The unit cell parameters a and b (along the [100] and [010]LCMO axes, respectively) of these manganite films are significantly (by ∼1.2%) increased as compared
to the corresponding values in the pseudocubic unit cell of bulk stoichiometric LCMO crystals. At T < 150 K, the temperature dependence of the resistivity of LCMO films is well described by the relation ρ = ρ1 + ρ2 (H) T
4.5. The value of ρ 2 decreases with increasing magnetic field and is close to the analogous coefficient for manganite films
grown on substrates with small lattice misfit. 相似文献
14.
S. T. Gao L. Y. Mu W. T. Wang M. H. Pu H. Zhang Y. Zhao 《Journal of Superconductivity and Novel Magnetism》2010,23(6):995-998
YBa2Fe3O8(YBFO) epitaxial films are prepared on (100) SiTrO3 single crystal substrate by polymer-assisted non-fluorine chemical solution deposition (CSD) method. The influence of firing
temperature on texture degree, microstructure, and physical properties of YBFO films is systematically investigated by x-ray
diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and SQUID magnetometer. YBFO film fired
at 1070 °C exhibits best epitaxial quality with FWHM value of (103) phi-scan and (005) omega-scan is 0.19° and 0.45°, respectively,
and highly dense and smooth morphology. A weak ferromagnetism transition was observed at 68 K in the YBFO film. 相似文献
15.
Liuqin Lai Yunhui Xu Yinjuan Ren Haobin Gao Xu Wang Jiliang Zhu Yusheng He Xiaohong Zhu 《Journal of Materials Science: Materials in Electronics》2017,28(8):5718-5724
Ba0.05Sr0.95TiO3 (BST), 5 mol% Mn-doped BST (Mn-BST) and bilayered Mn-BST/BST films with a thickness of about 100 nm were fabricated by using pulsed laser deposition technique on MgO single crystal substrates, and their microwave dielectric properties were comparatively investigated. It was confirmed that all the BST-based films were crystallized in pure single-oriented perovskite phase. There appeared nanosized pores in the BST film; after addition of Mn, however, the film surface morphology became denser while exhibiting an increased roughness, and ultimately, a smooth and dense morphology was achieved by the design of bilayered Mn-BST/BST film. Coherently, the microwave dielectric properties of BST films were enhanced by Mn doping and more significantly enhanced in the bilayered Mn-BST/BST film. As a result, for the bilayered film, a very low loss tangent of 0.017–0.007 and a high dielectric tunability of 70.9% under E?=?36 V/μm were simultaneously obtained at 79 K and L-band frequency (1–2 GHz), thereby resulting in an extremely high commutation quality factor of 14492. The excellent microwave dielectric properties obtained in the Mn-BST/BST bilayered film originate not only from the Mn-doping effect, but are also ascribed to the pre-deposition of BST layer, which serves as a good template for the growth of Mn-BST film. 相似文献
16.
Fe
x
Pt100−x
(70.1 ≤ x ≤ 83.4) thin films with ordered Fe3Pt phase were grown successfully onto MgO(110) substrates by electron beam evaporation. The unit cell of ordered Fe3Pt phase is elongated along c-axis direction and the thin films become more chemically ordered with decreasing Fe content. The magnetization of thin films
shows a decrease when Fe content is around 79 at.%. The relationship between magnetic anisotropy and structural parameters
suggests that the change of magnetic anisotropy in ordered Fe3Pt thin films with different compositions most likely stems from the magnetocrystalline origin. 相似文献
17.
We have studied the structure and magnetoresistance of 40-nm-thick epitaxial La0.67Ca0.33MnO3 (LCMO) films grown by laser deposition on (001)-oriented NdGaO3 (NGO) substrates. The manganite layers were oriented so that the b axis was perpendicular to the substrate plane and occurred under the action of inhomogeneous biaxial mechanical stresses.
The negative magnetoresistance of the LCMO films in the vicinity of the ferromagnetic spin ordering was about 71% (μ0
H = 1 T). The observed azimuthal anisotropy of the magnetotransport properties of 40-nm-thick LCMO/(001)NGO films can be explained
within the framework of a model of anisotropic magnetoresistance taking into account the presence of the preferred orientation
of the spontaneous magnetization. 相似文献
18.
Ashok Kumar R. S. Katiyar Ramesh Nath Premnath Carlos Rinaldi J. F. Scott 《Journal of Materials Science》2009,44(19):5113-5119
Layered nanostructures (LNs) of the commercial ferroelectric Pb(Zr0.53Ti0.47)O3 (PZT) and the natural ferroic relaxor Pb(Fe0.66W0.33)O3 (PFW) were fabricated with a periodicity of PZT/PFW/PZT (~5/1/5 nm, thickness ~250 nm) on MgO substrates by pulsed laser
deposition. The dielectric behavior of these LNs were investigated over a wide range of temperatures and frequencies, observing
Debye-type relaxation with marked deviation at elevated temperatures (>400 K). High dielectric constant and very low dielectric
loss were observed below 100 kHz and 400 K, whereas the dielectric constant decreases and loss increases with increase in
frequency, similar to relaxor ferroelectrics. Asymmetric ferroelectric hysteresis loops across UP and DOWN electric field
were observed with high remanent polarization (Pr) of about 33 μC/cm2. High imprint (~5–7 V across 250 nm thin films) were seen in ferroelectric hysteresis that may be due to charge accumulation
at the interface of layers or significant amount of strain (~3.21) across the layers. Room temperature ferromagnetic hysteresis
was observed with remanent magnetization 5.32 emu/cc and a coercive field of ~550 Oe. Temperature and field dependent leakage
current densities showed very low leakage ~10−7–10−5 A/cm2 over 500 kV/cm. We observed imprint in hysteresis that may be due to charge accumulation at the interface of layers or active
role of polar nano regions (PNRs) situated in the PFW regions. 相似文献
19.
The lateral unit cell parameter in nanodimensional La0.67Ca0.33MnO3 (LCMO) films grown on (001)-oriented LaAlO3 substrates is significantly (approximately 4%) smaller than the value measured along the normal to the substrate plane. At
T < 140 K, the temperature dependence of the resistivity ρ of LCMO films follows the relation ρ − ρ (T = 4.2 K) ≈ρ2(H)T
4.5, where ρ2 is independent of the temperature but decreases with increasing magnetic field H. It is shown that this decrease is related both to a decay of the spin waves in ferromagnetic domains and to the transformation
of antiferromagnetic phase inclusions into ferromagnetic ones. 相似文献
20.
Sushil Kumar M. A. Majeed Khan M. Zulfequar M. Husain 《Journal of Materials Science》2007,42(1):363-367
The fabrication of devices with lead salts and their alloys with detecting and lasing capabilities has been an important technological
development. The high quality polycrystalline thin films of PbTe1−x
S
x
with variable composition (0 ≤ x ≤ 1) have been deposited onto ultra clean glass substrates by vacuum evaporation technique. Optical, structural and electrical
properties of PbTe1−x
S
x
thin films have been examined. Absorption coefficient and band gap of the films were determined by absorbance measurements
in wavelength range 2,500–5,000 nm using FTIR spectrophotometer. Sample nature, crystal structure and lattice parameter of
the films were determined from X-ray diffraction patterns. DC conductivity and activation energy of the films were measured
in temperature range 300–380 K through I–V measurements. 相似文献