The Transient Behavior of Charges and Spins of La0.7Ca0.3MnO3 –the typical CMR material

Autor:	Hsin-Chia Ho, 何信佳
Rok vydání:	2004
Druh dokumentu:	學位論文 ; thesis
Popis:	92 The time-resolved photoreflectance and MOKE measurement systems are used to measure the carrier and spin dynamics of La0.7Ca0.3MnO3, a typical colossal magnetoresistance material (CMR). We have directly observed the transient behaviors of carrier and spin at different temperature and under differently external fields. They are evidenced that the spin relaxation time is faster than carrier relaxation time in this material. The relaxation processes of the spin are due to complex thermal equilibrium among the spin, electron, and lattice. The transient MOKE trace, which is independent of pumped polarization after the fastest relaxation time of spin at low temperature < Tc, will cool down the lattice temperature due to electron-spin interactions.
Databáze:	Networked Digital Library of Theses & Dissertations
Externí odkaz:	http://ndltd.ncl.edu.tw/handle/09811609036523212180 Zobrazit plný text záznamu