ACOUSTIC PROPERTIES OF BORATE GLASSES AT LOW-TEMPERATURES

被引：5

作者：

CARINI, G ^{[1
]}

CUTRONI, M ^{[1
]}

FEDERICO, M ^{[1
]}

GALLI, G ^{[1
]}

TRIPODO, G ^{[1
]}

机构：

[1] CNR,NAZL STRUTTURA MAT GRP,I-98100 MESSINA,ITALY

来源：

SOLID STATE COMMUNICATIONS | 1990年 / 74卷 / 07期

关键词：

D O I：

10.1016/0038-1098(90)90697-A

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

Ultrasonic measurements were performed in Ag2O-B2O3 glasses at low temperatures (1.5-30 K) in order to study the influence of the stoichiometry on the low energy excitations, generally represented in terms of two-level systems (TLS). The analysis of the acoustic attenuation, which is regulated by the mechanisms of the TLS-phonon assisted relaxation, permits to obtain the spectral density P of these excitations. The behaviour of P with Ag2O content is in contrast with the prediction of the free-volume theory. Moreover by considering the structural modifications of the glassy network, due to Ag2O, the non-bridging oxygens, which are formed in relevant number when an high content of metallic oxide is added to boron oxide are suggested as main microscopic origin of TLS's the non-bridging oxygens, which are formed in relevant number when a high content of metallic oxide is added to boron oxide. © 1990.

引用

页码：661 / 665

页数：5

共 28 条

[1] AG2O-B2O3 GLASSY SYSTEMS - NETWORK COHERENCE BEHAVIOR AS SEEN FROM MOLECULAR-DYNAMICS CALCULATIONS [J].