Abstract—

The heat capacity C_p(T) of cadmium fluoride, strontium fluoride, and the Cd_0.5Sr_0.5F₂ solid solution has been studied experimentally (2–300 K). We have detected deviations ΔC_p(T) of the C_p(T) data from additivity. The low-temperature (2–50 K), positive deviations ΔC_p(T) have been tentatively attributed to the effect of two-level systems associated with the glasslike character of the low-temperature thermal properties of the solution due to disorder in the Cd–Sr sublattice. The high-temperature (100–300 K), negative deviations ΔC_p(T) are caused by the effect of anharmonicity of lattice vibrations, whose increasing role is also associated with the disordered arrangement of atoms in the crystal lattice upon formation of the solution. The C_p(T) data for the solution of the system studied have been analyzed in the Debye–Einstein model. We have determined model parameters: characteristic temperatures Θ_i and the fractions of different contributions, a_i, to total thermal characteristics of the substances studied.

中文翻译：

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氟化镉和氟化锶之间固溶体的结构紊乱和热容

摘要-

已经通过实验研究了氟化镉，氟化锶和Cd _0.5 Sr _0.5 F ₂固溶体的热容C _p（T）（2-300 K）。我们检测到的偏差Δ Ç _p（Ť）所述的Ç _p（Ť）从加和数据。低温（2-50 K），正偏差Δ Ç _p（Ť）暂时归因于两级体系的影响，该体系与Cd–Sr子晶格中的无序性有关，具有溶液低温热性质的玻璃状特征。高温（100-300 K），负偏差Δ Ç _p（Ť）由晶格振动，其日益重要的作用也与在晶格中的原子的无序排列在形成的相关联的非谐的效果引起解。在Debye-Einstein模型中分析了所研究系统的解决方案的C _p（T）数据。我们已经确定模型参数：特征温度Θ_我和不同的贡献分数，，_即所研究物质的总热特性。