Electronic aspects of the ferromagnetic transition in manganese perovskites
- AT&T Bell Laboratories, 600 Mountain Avenue, Murray Hill, New Jersey 07974 (United States)
We have investigated the electronic structure associated with the ferromagnetic transition of La{sub 1{minus}{ital x}}Ca{sub {ital x}}MnO{sub 3} and La{sub 1{minus}{ital x}}Pb{sub {ital x}}MnO{sub 3} using high resolution photoemission, Mn 2{ital p} resonant photoemission, and O 1{ital s} x-ray absorption spectroscopies. The data clearly show that the band gap collapses below the Curie temperature ({ital T}{sub {ital C}}) and the density of states at the Fermi level increases with cooling, providing a conclusive microscopic evidence for an insulator-metal transition. Our results suggest that strong small polaron effects, which mainly contribute a charge fluctuation energy of {approximately}1.5 eV, are responsible for the insulating behavior above {ital T}{sub {ital C}} which has been enigmatic in the double-exchange model. {copyright} {ital 1996 The American Physical Society.}
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 285745
- Journal Information:
- Physical Review Letters, Vol. 76, Issue 22; Other Information: PBD: May 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electronic structure study of wide band gap magnetic semiconductor (La{sub 0.6}Pr{sub 0.4}){sub 0.65}Ca{sub 0.35}MnO{sub 3} nanocrystals in paramagnetic and ferromagnetic phases
Pressure and isotope effects in the manganese-oxide perovskites
Related Subjects
LANTHANUM OXIDES
PHASE TRANSFORMATIONS
CALCIUM OXIDES
MANGANESE OXIDES
LEAD OXIDES
LEAD ADDITIONS
ELECTRONIC STRUCTURE
PHOTOEMISSION
X-RAY SPECTROSCOPY
ABSORPTION SPECTRA
ENERGY-LEVEL DENSITY
DOPED MATERIALS
TEMPERATURE DEPENDENCE
SYNCHROTRON RADIATION
METAL-INSULATOR TRANSFORMATIONS