Defect dipole-induced domain reorientation of NdFeO3–PbTiO3 thin films

2018 ◽  
Vol 5 (5) ◽  
pp. 1156-1161 ◽  
Author(s):  
Yilin Wang ◽  
Hanqing Zhao ◽  
Kun Lin ◽  
Jinxia Deng ◽  
Jun Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Defect Dipole ◽  
Increasing Temperature ◽  
Domain Reorientation

The increasing temperature induces the realignment of the defect dipoles in NdFeO3–PbTiO3 thin films, which further reorients the domains.

The Effect of Microstructure and Processing Procedures on the Resistivity of Co-Sputtered W-Si Layers on GaAs Substrates

1990 ◽  
Vol 181 ◽  
Author(s):  
S. Carter ◽  
A. E. Staton-Bevan ◽  
D. A. Allan ◽  
J. Herniman
Keyword(s):  
Thin Films ◽  
Coarse Particles ◽  
Columnar Growth ◽  
Capping Layer ◽  
Resistivity Measurements ◽  
Growth Structure ◽  
Gaas Substrates ◽  
Increasing Temperature ◽  
The Relationship ◽  
Polycrystalline Mixture

ABSTRACTThe relationship between microstructure, composition, resistivity and processing procedures of W-Si layers on (100) GaAs was examined for both “as deposited” specimens and specimens annealed at temperatures between 100°C and 1000°C. TEM, EDAX, SIMS, AUGER and four point probe resistivity measurements were employed.The layers, exhibiting a columnar growth structure typical of sputter deposition, are amorphous below ≈ 800°C. At 700°C, the formation of pits, attributed to the outdiffusion of Ga and As into the W-Si layer, is observed at the W-Si/GaAs interface. The Ga and As outdiffusion was confirmed for temperatures above 700°C. The layers annealed between 800°C and 1000°C consist of a polycrystalline mixture of αW, βW and W5Si3 with coarse particles, thought to be W5Si3 precursors, formed along the W-Si/GaAs interface and protruding into the substrate. As the frequency of these protrusions increases with increasing temperature, the resistivity of the W-Si layers decreases.Both the composition and the resistivity of the W-Si thin films are affected by the processing procedure. The Si/W ratio of the W-Si thin films decreases whilst their resistivity significantly increases as a result of etching away the Si3N4 capping layer using HF. It is thought that this is due to the removal of Si-oxides formed within the layer during the W and Si sputtering. The decrease in the Si/W ratio and the increase in resistivity are not observed if an A1N capping layer is used.

Fabrication of CoNiP Thin Films with Improved Magnetic Property for Application in MEMS

2016 ◽  
Vol 860 ◽  
pp. 87-92 ◽  
Author(s):  
M.S. Haque ◽  
M.F. Rahman ◽  
M.M. Zaman ◽  
M.A. Matin ◽  
A.K.M.A. Hakim ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Ambient Temperature ◽  
Current Density ◽  
Copper Substrate ◽  
Cobalt Nickel ◽  
Magnetization Saturation ◽  
High Density Recording ◽  
Increasing Temperature ◽  
Cracking Tendency

This paper reports on fabricated hard magnetic cobalt nickel phosphorous (CoNiP) films with electro-chemically deposition technique on copper substrate in the presence of different urea (0 to 10 g/L) and NaH2PO2 (16 to 21 g/L) concentrations. Thin films were obtained at current density ranges from 5 to 20 mA/cm2 and temperature varies from ambient temperature to 60°C. Magnetic properties namely coercivity, remanent magnetization, saturation magnetization and squareness of the films were studied using Vibrating Sample Magnetometer (VSM). The result showed that for bath containing higher concentration of urea (10 g/L), bright films with higher coercivity were obtained at moderate current density (15 mA/cm2) and at higher temperatures (40-60°C). In contrary, uniform and bright films were produced at ambient temperature in bath containing no urea or lower concentration of urea. Scanning Electron Microscopy (SEM) revealed that porosity and cracking tendency are increased with increasing temperature. CoNiP thin films with improved magnetic properties are thus obtained for plausible applications in high density recording media and MEMS.

Electrical performance of alumina films made in EB evaporation

2016 ◽  
Vol 30 (20) ◽  
pp. 1650260 ◽  
Author(s):  
Li-Jun He ◽  
Li-Yan Wang ◽  
Wei-Zhong Chen ◽  
Xing-Zhao Liu
Keyword(s):  
Thin Films ◽  
Electron Beam ◽  
High Temperature ◽  
Trap Depth ◽  
Temperature Sensors ◽  
Important Application ◽  
Electrical Performance ◽  
Alumina Films ◽  
Increasing Temperature ◽  
Made In

Alumina thin films deposited by electron beam (EB) evaporation are investigated with regard to their performance in high-temperature electrical insulators. The most important application is high-temperature sensors. The leakage behavior of EB-evaporated alumina thin films is investigated by analyzing the temperature dependence of the I–V characteristics of alumina thin films deposited on Pt/n-Si(100) substrates. The temperature is extending in the range from 300 K up to 1273 K. The results show that ln(J) increases linearly with the increasing electric field at high-temperature range, the trap depth of [Formula: see text] is 280 meV, the conductivity increases with the increasing temperature, while the resistivity decreases with the increasing temperature.

Effect of Compressive Stress on Ferroelectric Aging Behavior of Hybrid-Doped Fe3+/Nb5+ BaTiO3 Ceramics

2009 ◽  
Vol 421-422 ◽  
pp. 259-262 ◽  
Author(s):  
Sasiporn Prasertpalichat ◽  
Muangjai Unruan ◽  
Thanapong Sareein ◽  
Jirapa Tangsritrakul ◽  
Athipong Ngamjarurojana ◽  
...  
Keyword(s):  
Electronic Device ◽  
Hysteresis Loops ◽  
Aging Effect ◽  
Aging Behavior ◽  
Dissipation Energy ◽  
Defect Dipole ◽  
Compressive Stresses ◽  
Energy Saturation ◽  
Titanate Ceramics ◽  
Domain Reorientation

Apart from aging effect, barium titanate ceramics usually subjected to the mechanical loading when it is used in electronic device. Thus, it is very interesting to investigate the influence of various compressive stresses on ferroelectric aging behavior of Ba(Ti0.99-xFe0.01Nbx)O3 , x=0.005-0.015. In this study, the P-E hysteresis loops were observed by using compressometer in conjunction with a modified Sawyer-Tower circuit. The stress level was varied from 0 to 185 MPa. The results showed that the dissipation energy, saturation polarization (Psat), remnant polarization (Pr) and the coercive field (Ec) decreased with increasing of stress. The aging behavior was still observed in acceptor-dominant of hybrid doped ceramics. The aging was also enhanced under application of the external stress. The explanation based on the defect-dipole and domain-reorientation processes was discussed.

Magnetic Films of Cobalt/Aluminum Electrodeposited from the Room Temperature Molten Salts AlCl3-BPC-CoCl2

2004 ◽  
Vol 59 (5) ◽  
pp. 519-524 ◽  
Author(s):  
Chao-Chen Yang ◽  
Te-Ho Wu ◽  
Min-Fong Shu
Keyword(s):  
Thin Films ◽  
Magnetic Force Microscopy ◽  
Room Temperature ◽  
Magnetic Force ◽  
Current Method ◽  
Magnetic Films ◽  
Deposition Potential ◽  
Force Microscopy ◽  
Atomic Force ◽  
Increasing Temperature

Abstract The electric conductivities of molten mixtures of aluminum chloride-butylpyridinium chloridecobalt chloride (AlCl3-BPC-CoCl2) were measured using a computerized direct-current method. The conductivities of all the melts increased with increasing temperature. The electrodeposition of Co/Al films from the AlCl3-BPC melt containing a small amount of CoCl2 has been studied by cyclic voltammetry. Compact and smooth Co/Al thin films could be obtained at a deposition potential of −0.4 V. The surface morphology and the composition of the electrodeposited thin films were studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The magnetic properties of the deposited thin films have been investigated via magnetic force microscopy (MFM) and vibrating sample magnetometry (VSM). Higher magnetization and smooth domains of Co/Al layers could be obtained at the deposition potentials of −0.1 V and −0.4 V, respectively.

Thermal expansion of the new perovskite substrates DyScO3 and GdScO3

2005 ◽  
Vol 20 (4) ◽  
pp. 952-958 ◽  
Author(s):  
M.D. Biegalski ◽  
J.H. Haeni ◽  
S. Trolier-McKinstry ◽  
D.G. Schlom ◽  
C.D. Brandle ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Rare Earth ◽  
Lattice Spacing ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Increasing Temperature

The thermal expansion coefficients of DyScO3 and GdScO3 were determined from298 to 1273 K using x-ray diffraction. The average thermal expansion coefficients of DyScO3 and GdScO3 were 8.4 and 10.9 ppm/K, respectively. No phase transitions were detected over this range, though the orthorhombicity decreased with increasing temperature. These thermal expansion coefficients are similar to other oxide perovskites (e.g., BaTiO3 or SrTiO3), making these rare-earth scandates promising substrates for the growth of epitaxial thin films of many oxide perovskites that have similar lattice spacing and thermal expansion coefficients.

Effect of Annealing on the Properties of thin Films of Free Base Phthalocyanine and Perylene-3,4,9,10-Tetracarboxylic Dianhydride Deposited by Organic Molecular Beam Deposition

1999 ◽  
Vol 560 ◽  
Author(s):  
S.M. Bayliss ◽  
S. Heutz ◽  
G. Rumbles ◽  
T.S. Jones
Keyword(s):  
Thin Films ◽  
Molecular Beam ◽  
Morphological Properties ◽  
Free Base ◽  
Force Microscopy ◽  
Molecular Beam Deposition ◽  
Increasing Temperature ◽  
Surface Morphologies ◽  
Tetracarboxylic Dianhydride ◽  
Beam Deposition

ABSTRACTOrganic molecular beam deposition (OMBD) has been used to deposit thin films of free base phthalocyanine (H2Pc) and perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). The structural, optical and morphological properties of the films have been measured as a function of annealing temperature using x-ray diffraction (XRD), electronic absorption spectroscopy and atomic force microscopy (AFM). A phase transition, (α-β), is observed for H2Pc films which is accompanied by changes in the bulk film properties and surface morphology. In the case of PTCDA increasing temperature does not affect the structural and optical properties of the film, but different surface morphologies are observed.

Photoluminescence and optical absorption in CaS : Eu2+ : Sm3+ thin films

1992 ◽  
Vol 7 (2) ◽  
pp. 411-417 ◽  
Author(s):  
J-G. Zhang ◽  
P.C. Eklund ◽  
Z.L. Hua ◽  
L.G. Salamanca-Riba ◽  
M. Wuttig ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Absorption ◽  
Energy Gap ◽  
Broad Band ◽  
Low Energies ◽  
Abnormal Increase ◽  
Temperature Spectra ◽  
Photoluminescence Studies ◽  
Increasing Temperature

The optical absorption and photoluminescence of Eu2+ : Sm3+-doped CaS films have been investigated in this paper. The energy dependence of the refractive index and absorption coefficient of the film were obtained by analyzing transmission and reflection spectra of the thin film. The refractive index at low energies is very close to the bulk value for CaS (n = 2.03) and decreases with increasing energy in the range of 1.2 to 2.5 eV. The energy gap of CaS: Eu2+ : Sm3+ thin films is found to be a direct gap with value Eg = 4.48 eV. Photoluminescence studies on annealed CaS: Eu2+ : Sm3+ thin films showed a broad band at ∼1.92 eV identified with emission from Eu2+ ions, and a set of sharp lines corresponding to emission from Sm3+ ions. Most of the strong features presented in the room temperature spectra are found in good agreement with previous bulk studies of CaS: Eu2+ and CaS: Sm3+. The abnormal increase of the Sm3+ photoluminescence with increasing temperature is explained by the phonon-assisted energy transfer from Eu2+ ions to Sm3+ ions.

Microstructure and Dielectric Properties of LiTiNiO Thin Films

2007 ◽  
Vol 336-338 ◽  
pp. 2635-2638
Author(s):  
Yan Dong ◽  
Bo Ping Zhang ◽  
Ya Ru Zhang ◽  
Jing Feng Li
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Frequency Stability ◽  
Dielectric Constants ◽  
Sem Images ◽  
Dense Microstructure ◽  
Increasing Temperature

LiTiNiO thin films were deposited on Pt/Ti/SiO2/Si(100) substrates using a sol-gel spin-coat method. The effects of annealing temperature and annealing time on microstructures and dielectric properties of the thin films were investigated. SEM images showed the thin films had uniform and dense microstructure and the grain size increased with increasing temperature and time. The LiTiNiO thin films consisted of complex oxides which proportions were mainly dependent on the annealing condition. The LiTiNiO thin film annealed at 600°C for 1h showed the highest dielectric constant and frequency stability, while prolonging annealing time even at 600°C resulted in the decrease in the frequency stability of the dielectric constants.

Measurement of Electrical Charge During Nanoindentation of Ferroelectric Thin Films

2000 ◽  
Vol 657 ◽  
Author(s):  
M. Algueró ◽  
A.J. Bushby ◽  
M.J. Reece
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Spherical Indenter ◽  
Ferroelectric Thin Films ◽  
Electrical Charge ◽  
Current Intensity ◽  
Indentation Force ◽  
Domain Reorientation ◽  
Distinct Maximum

Electrical charge transients have been measured during the nanoindentation of lanthanum modified lead titanate ferroelectric thin films. Using the spherical indenter as the top electrode, the films were locally poled. The films were then reindented at the exact same positions. The origin of the charge released is discussed in terms of piezoelectricity and depolarisation. The depolarisation must have been produced by a stress induced ferroelastic domain reorientation. Current intensity transients recorded during indentation showed a distinct maximum. This maximum corresponded to a force at which the depolarisation rate was a maximum. This provides the basis to define a coercive indentation force, and then a coercive indentation stress.

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