We have investigated thermal conductivities (κ) of polycrystalline Eu_1–xA_xTiO₃ (A = Ca, Sr, Ba, 0 ≤ x ≤ 0.8) bulk materials in the temperature range of ∼ 2 K < T < 1173 K. The EuTiO₃ demonstrates anomalous glass-like κ(T) behavior at low temperatures. Partial substitutions with Sr²⁺ and Ba²⁺ do not cause a significant change in the κ(T) behavior, while a κ(T) peak, which looks like a manifestation of a typical crystalline solid, appears only in the Ca-substituted samples with an orthorhombic structure when x ≥ 0.4. After excluding the magnetic effects on κ and discussing the possible phonon scattering mechanisms in depth, together with heat capacity C_p measurements and high-resolution X-Ray diffraction characterization, we find that the unusual low κ at low temperatures is attributed to resonant scattering induced by the intrinsic disordered local structure and lattice instability in EuTiO₃. Due to the different lattice dynamics of ATiO₃, the lattice structure of Eu_1–xCa_xTiO₃ can be regarded as formed by a part-soft (from EuTiO₃) part-rigid (from CaTiO₃) sublattice. The anomalous κ(T) behavior of Eu_1–xCa_xTiO₃ results from the combined effect of phonon transport between the normal phononic heat transport in the rigid sublattice and the strong damping of heat conduction in the soft sublattice.

我们研究了多晶 Eu _{1– x} A _x TiO ₃ ( A = Ca, Sr, Ba, 0 ≤ x ≤ 0.8) 散装材料在 ∼ 2 K < T < 1173 K温度范围内的热导率 ( κ )。 EuTiO ₃在低温下表现出异常的玻璃状κ ( T ) 行为。用 Sr ²⁺和 Ba ²⁺进行部分取代不会导致κ ( T ) 行为发生显着变化，而κ ( T) 峰，看起来像典型结晶固体的表现，仅在x ≥ 0.4时出现在具有正交结构的 Ca 取代样品中。在排除了对κ的磁效应并深入讨论了可能的声子散射机制后，结合热容量C _p测量和高分辨率 X 射线衍射表征，我们发现低温下异常低的κ归因于共振散射引起的EuTiO ₃中固有的无序局部结构和晶格不稳定性。由于A TiO _{3的不同晶格动力学，Eu 1– x}的晶格结构Ca _x TiO ₃可视为由部分软（来自EuTiO ₃）部分刚性（来自CaTiO ₃ ）亚晶格形成。Eu _{1– x} Ca _x TiO _3的反常κ ( T ) 行为是由刚性亚晶格中正常声子热传输与软亚晶格中热传导的强阻尼之间的声子传输的综合影响造成的。