|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'501'711
Articles rated: 2609
20 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
Complex charge ordering in CeRuSn | | R. Feyerherm
; E. Dudzik
; S. Valencia
; J. A. Mydosh
; Y.-K. Huang
; W. Hermes
; R. Pöttgen
; | | Date: |
24 Nov 2011 | | Abstract: | At ambient temperatures, CeRuSn exhibits an extraordinary structure with a
coexistence of two types of Ce ions in a metallic environment, namely trivalent
Ce3+ and intermediate valent Ce(4-x)+. Charge ordering produces a doubling of
the unit cell along the c-axis with respect to the basic monoclinic CeCoAl type
structure. Below room temperature, a phase transition with very broad
hysteresis has been observed in various bulk properties like electrical
resistivity, magnetic susceptibility, and specific heat. The present x-ray
diffraction results show that at low temperatures the doubling of the CeCoAl
type structure is replaced by an ill-defined modulated ground state. In this
state, at least three different modulation periods compete, with the dominant
mode close to a tripling of the basic cell. The transition is accompanied by a
significant contraction of the c axis. XANES data suggest that the average Ce
valence remains constant, thus the observed c axis contraction is not due to
any valence transition. We propose a qualitative structure model with modified
stacking sequences of Ce3+ and Ce(4-x)+ layers in the various modulated phases.
Surprisingly, far below 100 K the modulated state is sensitive to x-ray
irradiation at photon fluxes available at a synchrotron. With photon fluxes of
order 10E12/s, the modulated ground state can be destroyed on a timescale of
minutes and the doubling of the CeCoAl cell observed at room temperature is
recovered. The final state is metastable at 10 K. Heating the sample above 60 K
again leads to a recovery of the modulated state. Thus, CeRuSn exhibits both
thermally and x-ray induced reversible transformations of the Ce3+/Ce(4-x)+
charge ordering pattern. Such a behavior is unique among any know intermetallic
compound. | | Source: | arXiv, 1111.5693 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER