PRESSURE EFFECT ON THE GMR MATERIAL TL2MN2O7 WITH THE PYROCHLORE STRUCTURE

Citation
Yv. Sushko et al., PRESSURE EFFECT ON THE GMR MATERIAL TL2MN2O7 WITH THE PYROCHLORE STRUCTURE, Czechoslovak journal of Physics, 46, 1996, pp. 2003-2004
Citations number
9
Categorie Soggetti
Physics
ISSN journal
00114626
Volume
46
Year of publication
1996
Supplement
4
Pages
2003 - 2004
Database
ISI
SICI code
0011-4626(1996)46:<2003:PEOTGM>2.0.ZU;2-K
Abstract
The influence of hydrostatic pressure on the magnetic and electronic p roperties of a new class of manganese oxide-based giant magnetoresista nce (GMR) materials, represented by electron-doped Tl2Mn2O7, has been studied. It was found in this study, that the applied pressure causes the Curie temperature T-c of Tl2Mn2O7 to decrease at a modest rate of -1.6K/GPa. Negative pressure coefficient dTc/dP=-0.4 K/GPa was observe d for an isostructural insulator In2Mn2O7 as well. The results, togeth er with the temperature dependent multiple changes of the sign of the pressure coefficient of resistivity d rho/nP, are in sharp contrast wi th the case of the perovskite GMR oxides, where strong positive effect of pressure on both the T-c and conductivity was reported in agreemen t with a double exchange theory.