TEM characterization of CMR thin film on [001] SrTiO3 substrate

Author(s):  
Y.Y. Wang ◽  
A. Gupta ◽  
V.P. Dravid

Due to its potential magnetic device application, giant/colossal magnetoresistant (GMR or CMR) material, (bulk material as well as thin film), have been under intense investigation in recent years. In the bulk material, the changes of the resistivity under 4T magnetic field is about 80% at the metal-insulate transition temperature for La0.7Ca0.3MnO3 (LCMO). In 1994, S. Jin et al reported thousandfold change in resistivity in magnetoresistive La-Ca-Mn-0 films on a LaAlO3 substrate. It is suspected that such a large magnetoresistivity change in the thin film is due to the defect structure in the epitaxially grown thin film.The base structure of LCMO is an MnO6 octahedral perovskite cubic structure. Because of its strong static Jahn-Teller (JT) distortion, the compound is metrically orthorhombic, with a∼b∼√2 ap and c∼2ap where ap is the lattice constant for the base cubic structure. X-ray diffraction study on this compound shows that it belongs to Pnma space group.

2018 ◽  
Vol 924 ◽  
pp. 15-18
Author(s):  
Masashi Sonoda ◽  
Kentaro Shioura ◽  
Takahiro Nakano ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
...  

The defect structure at the growth front of 4H-SiC boules grown using the physical vapor transport (PVT) method has been investigated using high resolution x-ray diffraction and x-ray topography. The crystal parameters such as the c-lattice constant exhibited characteristic variations across the growth front, which appeared to be caused by variation in surface morphology of the as-grown surface of the boules rather than the defect structure underneath the surface. X-ray topography also revealed that basal plane dislocations are hardly nucleated at the growth front during PVT growth of 4H-SiC crystals.


2020 ◽  
Vol 12 (2) ◽  
pp. 254-262
Author(s):  
Kalyani Muninathan ◽  
Emerson Rajamony Navaneetha

At this present task, an attempt done in order to synthesize NiFeCo3O4 ternary thin film electrode by Electrodeposition method. Microstructure of the films studied using X-ray diffraction, energy dispersive X-ray spectroscopy (EDAX) and Field emission (FESEM) scanning electron microscopy. Films Electrochemical property were studied and confirmed with the help of charge discharge techniques using cyclic voltammetry, which confirms that the prepared electrode has excellent electrochemical capacitive behaviour with 757 F g–1 specific capacitance value of at the density in current about 1 mA g–1.


1997 ◽  
Vol 495 ◽  
Author(s):  
K. S. Weil ◽  
P. N. Kumta

ABSTRACTThe structures of four new tungsten based, ternary nitride compounds, Fe3W3N, Ni6W6N, Ni2W4N, and Fe4W2N, each prepared using a complexed precursor synthesis route, have been determined by Rietveld analyses of the respective powder x-ray diffraction (PXRD) data. Each compound crystallizes in a relatively complex cubic structure which is in general isostructural with the η-carbide structure. However, subtle structural differences which are compositionally dependent do exist between each nitride and these will be examined in detail in this paper.


1999 ◽  
Vol 77 (7) ◽  
pp. 515-520
Author(s):  
AAI Al-Bassam

Thin film polycrystalline solar cells based on CuIn1–xGaxSe2 have been fabricated and studied with x values from 0 to 1.0. The lattice parameters, grain size, and band gap were measured. Crystal structure and X-ray data of CuIn1–xGaxSe2 were determined using X-ray diffractometry. These materials had a cubic structure with x ≥ 0.5 and a tetragonal structure with x ≤ 0.5. The lattice constants vary linearly with composition. Grain size was measured using X-ray diffraction where the grain size increased linearly with Ga content. A grain size of 1.83-3.52 μm was observed with x ≤ 0.5, while it increased to 4.53 μm for x = 0.58.PACS No.: 70.73


1993 ◽  
Vol 29 (1) ◽  
pp. 300-306 ◽  
Author(s):  
J.A. Bain ◽  
B.M. Clemens ◽  
S.M. Brennan ◽  
H. Kataoka

2019 ◽  
Vol 15 (1) ◽  
pp. 30-38
Author(s):  
Darma Santi ◽  
Jacson Victor Morin

Characterization of merbau wood ash (Intsia, spp.) due to the influence of temperature and time of calcination has been studied. The variations in calcination temperature were 500 ᴼC (as M500) and 600 ᴼC (as M600), while the variations in the duration of calcination were 1, 2, and 3 hours, noted as M1, M2, and M3, respectively. Characterization was carried out using X-ray diffraction (XRD) and spectroscopic analysis using FT-IR. XRD results identified the presence of CaCO3 species (rhombohedral structure) and K2Si4O9 species with a hexagonal structure on M500. The M600 species identified Si (cubic structure), SiO2 (cubic structure), K2Si4O9 (hexagonal structure), and CaCO3 (rhombohedral structure). In general, the calcination temperature increases the crystallinity of several compounds contained in merbau wood ash. The length of time calcination reduces the absorption peak due to the decomposition and adsorption reactions of the presence of water molecules bound to the ash material of merbau wood (Intsia, spp).


Clay Minerals ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 249-260 ◽  
Author(s):  
A. Plançon ◽  
C. Zacharie

AbstractUntil recently, the determination of the defect structures (previously referred to incorrectly as “crystallinity”) of kaolinites has been obtained in one of two ways: (1) measurement of the Hinckley index, or (2) by comparing calculated X-ray diffraction patterns based on a model of the defect structure (including types of defects and abundances) with experimental diffraction profiles. The Hinckley method is simple and easy to perform but contains no real information about the defect structure. Calculated XRD patterns are based on real defects but these calculations are time consuming and require some skill in application. Another approach is proposed: an expert system which will accurately describe the defect structure of kaolinites based on a few measurements taken from a normal powder diffraction profile. This system has been verified for nine kaolinite samples for which the defect structure was previously determined by comparison of calculated and observed diffraction profiles. The expert system reproduced the correct defect structure for each of the samples.


2008 ◽  
Vol 368-372 ◽  
pp. 1130-1132
Author(s):  
Hong Zhi Wang ◽  
Qi Zhang ◽  
Yun Xin Gu ◽  
Yao Gang Li ◽  
Mei Fang Zhu

Ti0.6Cr0.4OxNy bimetallic metal oxynitride nano powder was synthesized by ammonolysis of the nanosized Cr2O3/TiO2 composite powder with n(Ti):n(Cr)=6:4 at 800oC for 8 h. The precursor and the resulting oxynitride were characterized by Auger electron spectroscope (AES), X-ray diffraction analysis (XRD), electron probe microanalysis (EPMA), transmission electron microscopy (TEM), and BET surface area techniques. The result indicated that the precursor was homogenous mixture of Cr2O3 and TiO2 with high BET surface area. The as-synthesized oxynitride powder contains only Ti0.6Cr0.4OxNy with cubic structure. The BET surface area of the oxynitride powder is 37.42 m2/g and the particle size is in the range of 20~30 nm.


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