Ultrasonic and Raman Spectroscopic Studies on Low-Energy Excitation of Alkali Metal Borate Glasses

碱金属硼酸盐玻璃低能激发的超声和拉曼光谱研究

• 批准号: 11650703
• 负责人: KODAMA Masao
• 金额: $ 1.98万
• 依托单位: Sojo University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650703/
• 关键词: glass; alkali metal borates; ultrasonic velocity; ultrasonic absorption; Raman spectroscopy; low-energy excitation; boson peak; anharmonicity; ホウ酸塩異常; 低温測定; 弾性定数

A glass exhibits an excess of low-energy phonon excitation (boson peak) over that of a crystal. One purpose of this project is to study the low-energy excitation by means of ultrasound and Raman spectroscopy. Another purpose of this project is to show that the fragility of a glass-forming liquid is related to the anharmonicity of the resulting glass. The glass studied is the binary system of lithium borate glasses.(1) The density, the linear expansion coefficient and the change in ultrasonic velocity with temperature were measured for lithium borate glasses, from which the Gruneisen constant representing the anharmonicity was determined ; (2) The Gruneisen constant was also evaluated by analyzing the boson peak of Raman scattering on the basis of a theory that the boson peak is caused by an anharmonic vibration of atomic groups present in the glass-forming cluster. (3) It was found that the two sets of Gruneisen constant were in close agreement. (4) The temperature range of the glass transition was determined by differential thermal analysis and the fragility was evaluated from Tg/ΔT, where Tg and ΔT are the onset temperature of glass transition and the temperature width of glass transition, respectively, (5) It was found that the dependence of the Gruneisen constant on the glass composition is in close agreement with the dependence of the fragility on the glass composition.(6) It was concluded then that the fragility and the anharmonicity are interrelated with one another.

玻璃比晶体表现出多余的低能声子激发（玻色子峰值）。本项目的目的之一是利用超声和拉曼光谱研究低能激发。这个项目的另一个目的是表明玻璃形成液体的易碎性与产生的玻璃的非调和性有关。所研究的玻璃为硼酸锂二元体系玻璃。(1)测量了硼酸锂玻璃的密度、线性膨胀系数和超声速度随温度的变化，确定了代表非调和性的Gruneisen常数；(2)基于玻色子峰是由玻璃形成团簇中原子群的非谐振动引起的理论，通过分析拉曼散射的玻色子峰，计算了Gruneisen常数。(3)发现两组Gruneisen常数非常吻合。(4)通过差热分析确定了玻璃化转变的温度范围，并通过Tg/ΔT评价了玻璃化转变的脆性，其中Tg和ΔT分别为玻璃化转变的起始温度和玻璃化转变的温度宽度。(5)发现Gruneisen常数对玻璃组成的依赖关系与脆性对玻璃组成的依赖关系非常一致。(6)脆弱性与非和谐性是相互关联的。

项目成果

M,Kodama: "Thermal and Mechanical Properties of Lithium Borate Glassess in Relation to the Glass Structre"Joumal of Themal Analysis and Calorimetry. 57. 787-796 (1999)

M，Kodama：“硼酸锂玻璃与玻璃结构相关的热学和机械性能”热分析与量热学杂志。

S.Kojima, V.N.Novikov, and M.Kodama: "Fast Relaxation, Boson Peak, and Anharmonicity in Li_2O-B_2O_3 Glasses"J.Chem.Phys.. Vol.113, No.15. 6344-6350 (2000)

S.Kojima、V.N.Novikov 和 M.Kodama：“Li_2O-B_2O_3 玻璃中的快速弛豫、玻色子峰和非和谐性”J.Chem.Phys. 第 113 卷，第 15 期。

M.Kodama: "Thermal and Mechanical Properties of Lithium Borate Glasses in Relation to the Glass Structure"Journal of Thermal Analysis and Calorimetry. 57. 787-796 (1999)

M.Kodama：“硼酸锂玻璃的热性能和机械性能与玻璃结构的关系”热分析与量热学杂志。

M.Kodama: "Thermal and Mechanical Proterties of Lithium Borate Glasses in Relation to the Glass Structure"Journal of Thermal Analysis and Calorimetry. 57. 787-796 (1999)

M.Kodama：“与玻璃结构相关的硼酸锂玻璃的热和机械性能”热分析与量热学杂志。

S.Kojima: "Boson Peak in Modified Borate Glasses"Physica B. 263-264. 336-338 (1999)

S.Kojima：“改良硼酸盐玻璃中的玻色子峰”Physica B. 263-264。