Colossal Magnetoresistance in Thick La0.7Ca0.3MnO3 Films

1995 ◽  
Vol 384 ◽  
Author(s):  
Randolph E. Treece ◽  
P. Dorsey ◽  
M. Rubinstein ◽  
J. M. Byers ◽  
J. S. Horwitz ◽  
...  
Keyword(s):  
Colossal Magnetoresistance ◽  
Single Phase ◽  
Laser Deposition ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Post Deposition Annealing ◽  
X Ray ◽  
Mr Effect ◽  
Deposited Films ◽  
Post Deposition

ABSTRACTThick films (0.6 and 2.0 μm) of the colossal magnetoresistance (CMR) material, La0.7Ca0.3MnO3 (LCMO), have been grown by pulsed laser deposition (PLD). The films were grown from single-phase LCMO targets in 100 mTorr 02 pressures and the material deposited on (100) LaAlO3 substrates at deposition temperatures of 800°C. The deposited films were characterized by X-ray diffraction (XRD), magnetic field-dependent resistivity, and Rutherford backscattering spectroscopy (RBS). The LCMO films were shown by XRD to adopt an orthorhombic structure. Brief post-deposition annealing led to ~50,000% and ~12,000% MR effect in the 0.6 μm and 2.0 μm films, respectively.

The Structure and Electric Field Dependent Dielectric Properties of Annealed Sr1−xBaxTio3 Ferroelectric Thin Films

1995 ◽  
Vol 401 ◽  
Author(s):  
L.A. Knauss ◽  
J.M. Pond ◽  
J.S. Horwitz ◽  
C.H. Mueller ◽  
R.E. Treece ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Single Phase ◽  
Pulsed Laser ◽  
Lattice Parameter ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Deposited Films ◽  
Post Deposition

AbstractThe effect of a post deposition anneal on the structure and dielectric properties of epitaxial Sr1−x, BaxTiO3 (SBT) thin films with x = 0.35, 0.50 and 0.60 has been measured. The films were grown by pulsed laser deposition on LaAlO3(001) substrates at 750°C in 350 mTorr of oxygen. The asdeposited films were single phase, (001) oriented with 0)-scan widths for the (002) reflection between 0.160 and 0.50'. The dielectric properties of the as-deposited films exhibit a broad temperature dependence and a peak which is as much as 50 K below the peak in bulk SBT. Also, the lattice parameter, as measured by x-ray diffraction, of the as-deposited films was larger than the bulk indicating strain in the films. The as-deposited films were annealed for 8 hours at 900°C in oxygen. The dielectric properties of the annealed films were closer to that of bulk SBT and the lattice parameter was closer to the bulk lattice parameter indicating a reduction of strain. Annealing of as-deposited films also resulted in an increased dielectric tuning without increased dielectric loss.

Study of Raman Spectrum of Fe Doped CeO2 Thin Films Grown by Pulsed Laser Deposition

2010 ◽  
Vol 123-125 ◽  
pp. 375-378 ◽  
Author(s):  
Ram Prakash ◽  
Shalendra Kumar ◽  
Chan Gyu Lee ◽  
S.K. Sharma ◽  
Marcelo Knobel ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Single Phase ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Fe Doping ◽  
Full Width ◽  
Deposition Technique ◽  
X Ray Diffraction ◽  
X Ray

Ce1-xFexO2 (x=0, 0.01, 0.03 and 0.0 5) thin films were grown by pulsed laser deposition technique on Si and LaAlO3 (LAO) substrates. These films were deposited in vacuum and 200 mTorr oxygen partial pressure for both the substrates. These films were characterized by x-ray diffraction XRD and Raman spectroscopy measurements. XRD results reveal that these films are single phase. Raman results show F2g mode at ~466 cm-1 and defect peak at 489 cm-1 for film that deposited on LAO substrates, full width at half maximum (FWHM) is increasing with Fe doping for films deposited on both the substrates.

Mullite formation from nonstoichiometric slow hydrolyzed single phase gels

1995 ◽  
Vol 10 (4) ◽  
pp. 912-917 ◽  
Author(s):  
Yong Wang ◽  
William J. Thomson
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crystalline Phase ◽  
Single Phase ◽  
Formation Temperature ◽  
Mullite Formation ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spinel Formation

A comparative dynamic x-ray diffraction (DXRD) and differential thermal analysis (DTA) study was performed in the investigation of mullite and spinel formation from slowly hydrolyzed single phase gels with Al/Si ratios ranging from 1/1 to 14/1. Both metastable tetragonal mullite and spinel were observed to form at temperatures <1000 °C in the gels with Al/Si ratios <8/1 and mullite transformed to the orthorhombic structure at ∼1250 °C. However, at higher Al/Si ratios, spinel was the only crystalline phase detected at <1000 °C and orthorhombic mullite formed directly at temperatures >1250 °C. As the Al/Si ratio increases, both the tetragonal mullite and spinel formation temperatures decrease while the orthorhombic mullite formation temperature increases. Based on the Al/Si composition where the formation extents of tetragonal mullite and spinel were maximum, their compositions are estimated to be 2Al2O3 · SiO2 and 6A12O3 · SiO2, respectively.

INFLUENCE OF SAMARIUM SUBSTITUTION ON IMPEDANCE DIELECTRIC AND ELECTROMECHANICAL PROPERTIES OF Pb(1-x)K2xNb2O6

2007 ◽  
Vol 21 (06) ◽  
pp. 931-945 ◽  
Author(s):  
K. SAMBASIVA RAO ◽  
P. MURALI KRISHNA ◽  
D. MADHAVA PRASAD ◽  
JOON HYUNG LEE
Keyword(s):  
Impedance Spectroscopy ◽  
Room Temperature ◽  
Single Phase ◽  
Piezoelectric Properties ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Electromechanical Properties ◽  
X Ray ◽  
Different Temperatures ◽  
Ferroelectric Hysteresis

Ferroelectric, hysteresis, impedance spectroscopy parameters, AC conductivity, and piezoelectric properties in the ceramics of Pb 0.74 K 0.52 Nb 2 O 6 and Pb 0.74 K 0.13 Sm 0.13 Nb 2 O 6 have been studied. X-ray diffraction study reveals single phase with the orthorhombic structure. The samples were characterized for ferroelectric and impedance spectroscopy properties from room temperature to 600°C. Cole–Cole plots (Z″ versus Z′) are drawn at different temperatures. The results obtained are analyzed to understand the conductivity mechanism in both the samples. The piezoelectric constant d33 has been found to be 96 × 10-12 C/N in PKN.

Thin Film Deposition and Transport in 2223 Bi‐Sr‐Ca‐Cu‐O

1989 ◽  
Vol 169 ◽  
Author(s):  
J.T. Kucera ◽  
D.G. Steel ◽  
D.W. Face ◽  
J.M. Graybeal ◽  
T.P. Orlando ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
Post Deposition Annealing ◽  
X Ray ◽  
Annealing Conditions ◽  
Sensitive Function ◽  
Post Deposition

AbstractWe have reproducibly prepared thin films of Bi‐Sr‐Ca‐Cu‐O with Tc ≥ 105K. Depositions were done at ambient temperature with a subsequent post‐deposition anneal, and did not include lead substitution. X‐ray diffraction data indicates a majority fraction of the 2223 phase. These films possess very large grains of the order of 20‐30 u.m in size. Post‐deposition annealing conditions are a sensitive function of composition. Detailed transport measurements as a function of temperature and magnetic field have been obtained.

Effect of Post-Deposition Annealing on some Optical Properties of Thermally-Evaporated V2O5 Thin Film

2012 ◽  
Vol 329 ◽  
pp. 139-145
Author(s):  
S.A. Aly
Keyword(s):  
Optical Properties ◽  
Amorphous State ◽  
X Ray Diffraction ◽  
Post Deposition Annealing ◽  
X Ray ◽  
Spectral Behaviour ◽  
Before And After ◽  
Different Temperatures ◽  
Reflectance Measurements ◽  
Post Deposition

A Vanadium Pentoxide Sample with a Film Thickness of 75 Nm Has Been Thermally Evaporated on Unheated Glass Substrate Using V2O5High Purity Powder. the Sample Was Subjected to a Subsequent Post-Deposition Annealing in Air at Different Temperatures for a Period of One Hour. the Optical Properties Were Studied by Transmittance and Reflectance Measurements. the Integrated Visible ,TVis, and Solar, TSol, Transmittance Were Calculated. the Spectral Behaviour of the Refractive Index as Well as the Absorption Coefficient before and after Post-Deposition Heat-Treatment Was Also Reported. X-Ray Diffraction Confirmed that the Film in the as-Deposited as Well as after Annealing up to 400 °C Is in the Amorphous State.

Crystallization of yttrium-iron garnet (YIG) in thin films: Nucleation and growth aspects

2007 ◽  
Vol 1036 ◽  
Author(s):  
Michael V. Zaezjev ◽  
Manda Chandra Sekhar ◽  
Marcello Ferrera ◽  
Luca Razzari ◽  
Barry M Holmes ◽  
...  
Keyword(s):  
Thin Films ◽  
Yttrium Iron Garnet ◽  
Single Phase ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Yttrium Iron ◽  
Iron Garnet ◽  
Parasitic Phase ◽  
Deposited Films ◽  
Post Deposition

AbstractWe have studied the crystallization of the yttrium - iron garnet (Y3Fe5O12, YIG) polycrystalline phase in thin films fabricated by means of pulsed laser deposition . Films were deposited on MgO substrates in vacuum, in argon, and in oxygen. A subsequent post-deposition heat treatment (annealing) was done at 800°C in air. We have shown that the crystallization of YIG was precluded by co-existent parasitic phases present in the as-deposited films. Specifically, the growth of the parasitic phase needs to be suppressed in order to get a single-phase polycrystalline YIG. Lowering the substrate temperature has been shown to be a simple and efficient way to suppress the growth of parasitic phase and to obtain good quality YIG films after thermal treatment. This procedure has been demonstrated to be successful even when the YIG films were grown in vacuum and their composition was significantly out of stoichiometry.

STRUCTURE AND SUPERCONDUCTING CHARACTERISTICS OF A DEFECTIVE (Bi1.6Pb0.4)(Sr1.8Ba0.2)(Ca1.96Lu0.04)Cu3Oy SUPERCONDUCTOR

2001 ◽  
Vol 15 (02) ◽  
pp. 157-165
Author(s):  
D. CIURCHEA
Keyword(s):  
Coherence Length ◽  
Single Phase ◽  
Three Dimensional ◽  
Direct Consequence ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Pattern Decomposition

Full pattern decomposition was applied to the X-ray diffraction patteren of a single phase orthorhombic ( Bi 1.6 Pb 0.4)( Sr 1.8 Ba 0.2)( Ca 1.96 Lu 0.04) Cu 3 O y superconductor. Delocalization of the Sr atoms induces terracing of the Cu/Ca/Cu superconducting stacking up to 0.6 Å, in the range of the c-axis coherence length. This yields a three dimensional character of the conduction evidenced in the resistivity measurements also. The effect is direct consequence of the loss of symmetry implied by the orthorhombic structure.

Synchrotron X-ray Diffraction Study of Single-Phase β-AlN Thin Films Heteroepitaxially Grown on Sapphire (0001) Substrates by Pulsed Laser Deposition

2010 ◽  
Vol 49 (2) ◽  
pp. 020212 ◽  
Author(s):  
Kazushi Sumitani ◽  
Ryota Ohtani ◽  
Tomohiro Yoshida ◽  
You Nakagawa ◽  
Satoshi Mohri ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Diffraction Study ◽  
Single Phase ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray

Rietveld refinement of X-ray powder diffraction data of Sm0.55Sr0.45MnO3 polycrystalline material

2015 ◽  
Vol 31 (1) ◽  
pp. 77-79 ◽  
Author(s):  
G. Murugesan ◽  
R. Nithya ◽  
S. Kalainathan
Keyword(s):  
Solid State ◽  
Single Phase ◽  
Polycrystalline Material ◽  
General Structure ◽  
Powder Diffraction Data ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
General Structure Analysis System ◽  
Analysis System

Polycrystalline Sm0.55Sr0.45MnO3 was prepared by solid-state reaction at 1300 °C. Single phase of the compound was analysed by a powder X-ray diffraction technique. The powder pattern of Sm1−xSrxMnO3 was indexed and refined using a General Structure Analysis System (GSAS) to an orthorhombic structure with space group Pnma, a = 5.4323(7), b = 7.6585(4), and c = 5.4343(7) Å.

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