Low-energy magnetic excitations in the Pr metaphosphate glass

被引:35
作者
Carini, G
DAngelo, G
Tripodo, G
Fontana, A
Rossi, F
Saunders, GA
机构
[1] UNIV MESSINA,IST NAZL FIS MAT,I-98166 SANT AGATA,ME,ITALY
[2] UNIV TRENT,DIPARTIMENTO FIS,I-38050 POVO,TN,ITALY
[3] UNIV TRENT,IST NAZL FIS MAT,I-38050 POVO,TN,ITALY
[4] UNIV BATH,SCH PHYS,BATH BA2 7AY,AVON,ENGLAND
来源
EUROPHYSICS LETTERS | 1997年 / 40卷 / 04期
关键词
D O I
10.1209/epl/i1997-00484-4
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
Large magnetic contributions to the low-temperature specific heats of rare-earth metaphosphate (R2O3)(0.25)(P2O5)(0.75) glasses have been observed. These effects result from electronic transitions between 4f levels multiply split due to local disorder, which also give rise to a strong electronic contribution to the low-frequency Raman scattering at low temperatures in the Pr metaphosphate glass. By contrast Sm and Gd metaphosphate glasses show the usual spectral features for a glass: the quasielastic scattering and the boson peak. Both the thermal and optical characteristics in the Pr glass are associated with a very large density of low-lying magnetic excitations, induced by the topological disorder. Using the electronic low-frequency Raman scattering at 1.5 K, which reflects this high density of low-energy states, it has proved possible to fit the magnetic contribution to the low-temperature specific heat in the Pr glass.
引用
收藏
页码:435 / 440
页数:6
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