Accession Number:

ADP011913

Title:

Effect of Pressure and Magnetic Field on the Phase Transitions in Lanthanum-Deficient Manganites

Descriptive Note:

Conference proceedings

Corporate Author:

POLISH ACADEMY OF SCIENCES WARSAW INSTOF PHYSICS

Report Date:

2001-01-01

Pagination or Media Count:

4.0

Abstract:

We report on the pressure, field and temperature dependencies of magnetization and resistance in manganites of La1-xCax1-y Mn1yO3 type. The MT dependencies is established to exhibit the following peculiarities the first is connected with the paramagnet PM -ferromagnet FM transition at 267 K the peak of MT dependence at 263 K is presumably due to an existence of AFM clusters an anomaly in magnetization as well as in susceptibility is connected with the FM - canted phase transition at 42 K and the large irreversibility in the field-cooled and zero field-cooled magnetization. As field is increased above 200 Oe, the sign of the MT anomaly changes , namely, the MT magnetization increases with increasing field at 42 K. The character of MT dependencies does not change under pressure. However, both the Curie temperature, Tsub c, and the resistance peak Tsub maxR corresponding to metal-insulator transition shift in the direction of high temperatures with increasing pressure. A pressure stabilizes the ferromagnetic metallic phase. The temperature of the FM - canting phase transition does not change under pressure. The magnetoresistance effect increases by 15 under pressure of 12.6 kbar. The linear increasing of Tsub c with the derivatives of dTsub cdP approx. 1.5 K kbar in La0.7Ca0.30.,8Mn1.2O3 and dTsub cdP approx. 1.9 K kbar in La0.6Mn1.4O3 ceramics was observed at pressure up to 10 kbar. The Tsub maxR

Subject Categories:

  • Physical Chemistry
  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE