ISSN:
1572-9540
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Mössbauer studies of 151Eu in Eu2VO4 reveal a very sharp valence averaging phase transition at 450 K. Two equally intense absorption lines, differing in isomer shift by 12.7 mm/s, corresponding to Eu2+ and Eu3+, collapse to a single absorption line at the average isomer shift. The transition is confirmed by X-ray and resistivity measurements. In RSr2Fe3O9 (R=Pr, Sm) 57Fe studies reveal averaging valence phase transitions coinciding with magnetic order phase transitions at 190 K and 140 K, respectively. Two magnetic sextets, corresponding to 2Fe3+ + Fe5+, collapse to two singlets corresponding to 2Fe4+ + Fe3+.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1012655620041
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