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ID 18720
file
creator
Matsuhata, Hirofumi
Iga, Fumitoshi
Tsubota, Masami
Nakano, Toshihiro
Kato, Kenichi
abstract
Structural changes in Y1-xCaxTiO3 (x=0.37, 0.39 and 0.41) during a transition from an insulator-to-metal were investigated by transmission electron microscopy. In a specimen for x=0.39, on cooling a transition from orthorhombic to monoclinic lattice was observed first. The onset of this transition was not certain, but the monoclinic lattice was clearly observed at 170 K. On further cooling to 140 K, approximately the metalinsulator transition temperature, an introduction of strain to this monoclinic phase was observed. Below 140 K a state of phase separation, with growth of domains, was observed. In the insulator specimen for x=0.37 the transition from orthorhombic to monoclinic lattice was observed similarly to the case of x=0.39, but no phase separation was observed in the range from room temperature to 110 K. In the case for x=0.41, the phase separation was also observed on cooling, but transition temperature of the phase separation is lower than that reported by x-ray diffraction. The phase separation observed presently for 0.39 and 0.41 is considered to be a kind of electrical phase separation, which drives the appearance of the metallic state at low temperatures. This is the first report on observation of separated domains on the electrical phase separation associated with the metal-insulator transition in paramagnetic Y1-xCaxTiO3.
journal title
Physical Review B - Condensed Matter and Materials Physics
volume
Volume 70
issue
Issue 13
start page
134109-1
end page
134109-6
date of issued
2004-10-26
publisher
American Physical Society
issn
0163-1829
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
rights
Copyright (c) 2005 American Physical Society.
relation url
department
Graduate School of Advanced Sciences of Matter