Grain-boundary room-temperature low-field magnetoresistance in Sr2FeMoO6 films

2000 ◽  
Vol 87 (9) ◽  
pp. 6761-6763 ◽  
Author(s):  
H. Q. Yin ◽  
J.-S. Zhou ◽  
R. Dass ◽  
J.-P. Zhou ◽  
J. T. McDevitt ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Room Temperature ◽  
Low Field

scholarly journals Effects of Organic Material on Magnetoresistance in Electron-doped Double Perovskite

2021 ◽  
Author(s):  
Ya Fang Li ◽  
Yu Liu ◽  
Yan-Ming Zhang ◽  
Jin-Feng Wang
Keyword(s):  
Oleic Acid ◽  
Grain Boundary ◽  
Small Molecules ◽  
Room Temperature ◽  
Double Perovskite ◽  
Double Perovskites ◽  
Low Field ◽  
Band Filling ◽  
High Spin Polarization ◽  
Magnetoresistance Property

Abstract The Curie temperature of electron-doped Sr2FeMoO6 can be optimized significantly due to the band-filling effect, but accompanying an almost absent low-field magnetoresistance (LFMR), which is unfavorable to applications in the magnetoresistive devices operated at room-temperature. Our previous works confirmed that, a remarkable enhanced LFMR was observed in Sr2FeMoO6 by modifying the grain boundary with insulating organic small molecules (glycerin, CH2OHCHOHCH2OH). However, in this work, modifying the grain boundary strength of the La0.5Sr1.5FeMoO6 with the insulating organic macromolecules (oleic acid, CH3(CH2)7CH=CH(CH2)7COOH) or small molecules (glycerin), both of them have negligible functions on the magnetoresistance behavior in La0.5Sr1.5FeMoO6. Contrary to the glycerin-modified Sr2FeMoO6, Sr2FeMoO6/oleic acid composites don’t exhibit an obviously increased magnetoresistance property. Based on the above experimental results and the related works, it is proposed that, maintaining high spin polarization of the carriers at the Fermi level and improving the tunneling process across the grain boundary by using the suitable organic materials are decisive factors for optimizing the magnetoresistance behavior in the similar electron-doped double perovskites.

Dependence of Intergranular Fracture on Boundary Topography and Cohesion

1973 ◽  
Vol 31 ◽  
pp. 150-151
Author(s):  
J. E. Doherty ◽  
A. F. Giamei ◽  
B. H. Kear ◽  
C. W. Steinke
Keyword(s):  
Grain Boundary ◽  
Room Temperature ◽  
Nickel Base Superalloy ◽  
Boundary Shear ◽  
Room Temperature Ductility ◽  
Solid Solution Matrix ◽  
Nickel Base ◽  
Solution Matrix ◽  
Different Levels ◽  
Base Superalloy

Recently we have been investigating a class of nickel-base superalloys which possess substantial room temperature ductility. This improvement in ductility is directly related to improvements in grain boundary strength due to increased boundary cohesion through control of detrimental impurities and improved boundary shear strength by controlled grain boundary micros true tures.For these investigations an experimental nickel-base superalloy was doped with different levels of sulphur impurity. The micros tructure after a heat treatment of 1360°C for 2 hr, 1200°C for 16 hr consists of coherent precipitates of γ’ Ni3(Al,X) in a nickel solid solution matrix.

Characterization of intergranular cuprous oxide in polycrystalline YBa2Cu3O7-x

1988 ◽  
Vol 46 ◽  
pp. 880-881
Author(s):  
Bradley L. Thiel ◽  
Chan Han R. P. ◽  
Kurosky L. C. Hutter ◽  
I. A. Aksay ◽  
Mehmet Sarikaya
Keyword(s):  
Grain Boundary ◽  
Cuprous Oxide ◽  
Room Temperature ◽  
Boundary Phase ◽  
Spectroscopic Techniques ◽  
Transition Width ◽  
Practical Applications ◽  
Thin Foils ◽  
Superconducting Oxides

The identification of extraneous phases is important in understanding of high Tc superconducting oxides. The spectroscopic techniques commonly used in determining the origin of superconductivity (such as RAMAN, XPS, AES, and EXAFS) are surface-sensitive. Hence a grain boundary phase several nanometers thick could produce irrelevant spectroscopic results and cause erroneous conclusions. The intergranular phases present a major technological consideration for practical applications. In this communication we report the identification of a Cu2O grain boundary phase which forms during the sintering of YBa2Cu3O7-x (1:2:3 compound).Samples are prepared using a mixture of Y2O3. CuO, and BaO2 powders dispersed in ethanol for complete mixing. The pellets pressed at 20,000 psi are heated to 950°C at a rate of 5°C per min, held for 1 hr, and cooled at 1°C per min to room temperature. The samples show a Tc of 91K with a transition width of 2K. In order to prevent damage, a low temperature stage is used in milling to prepare thin foils which are then observed, using a liquid nitrogen holder, in a Philips 430T at 300 kV.

Room-temperature grain boundary diffusion data measured from historical artifacts

2005 ◽  
Vol 96 (10) ◽  
pp. 1187-1192 ◽  
Author(s):  
Raymond J. Kremer ◽  
Mysore A. Dayananda ◽  
Alexander H. King
Keyword(s):  
Grain Boundary ◽  
Room Temperature ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Diffusion Data

Two-Dimensional Room-Temperature Giant Antiferrodistortive SrTiO3 at a Grain Boundary

2021 ◽  
Vol 126 (22) ◽  
Author(s):  
Bo Han ◽  
Ruixue Zhu ◽  
Xiaomei Li ◽  
Mei Wu ◽  
Ryo Ishikawa ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Room Temperature ◽  
Two Dimensional

Phase Relationship Studies of Silicon Nitride System—A Key to Materials Design

1992 ◽  
Vol 287 ◽  
Author(s):  
T.S. Yen ◽  
W.Y. Sun
Keyword(s):  
Elevated Temperature ◽  
Silicon Nitride ◽  
Grain Boundary ◽  
Phase Behavior ◽  
Phase Diagrams ◽  
Room Temperature ◽  
Phase Relationship ◽  
Materials Design ◽  
Basic Approach ◽  
System A

ABSTRACTAdditions and revisions to several of the most important phase diagrams and phase behavior diagrams in the silicon nitride field are reviewed in this work, with emphasis on the Y-Si-A1-O-N system. This information is further used to make observations on the promising silicon nitride systems containing either highly refractory grain boundary phases or compatible matrix phases of desirable properties. Examples are provided to illustrate the advantage of such a basic approach to materials design. Hardness, toughness, strength at room temperature and elevated temperature and even sinterability can all be improved by adopting such an approach.

Room-temperature and low-field magnetoresistance of La-Sr-Mn-O thin films

1999 ◽  
Vol 35 (5) ◽  
pp. 2844-2846 ◽  
Author(s):  
Kyung-Ku Choi ◽  
T. Taniyama ◽  
Y. Yamazaki
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Low Field
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