AI 中文总结
研究通过张量分析和群论，从晶体学点群对称性确定物理性质张量等，应用于PZT。发现相图中对称性降低影响相关张量分量及拉曼振动对称性分类，揭示转变本质，强调晶体对称性分析对解释铁电钙钛矿氧化物性质的重要性。
AI 中文摘要
晶体对称性控制着功能材料的宏观物理性质和晶格动力学。我们提出了张量分析和群论的系统应用，以直接从晶体学点群对称性确定允许的物理性质张量、振动模式对称性和拉曼选择规则。该方法应用于典型铁电体PbZr_xTi_1-xO_3（PZT）。PZT相图中的对称性降低增加了独立热释电、介电和压电张量分量的数量，并改变了拉曼活性振动的对称性分类。这些模式分类使得能够基于对称性对已报道的室温粉末拉曼光谱进行分解，揭示了四方到菱面体转变是光谱强度的连续重新分布，而非新拉曼模式的出现。选定模式中持续的子峰结构表明由于阳离子无序和晶格非谐性导致的局部对称性破坏，强调了晶体对称性分析对解释铁电钙钛矿氧化物功能和振动特性的重要性。
英文摘要
Crystal symmetry governs macroscopic physical properties and lattice dynamics in functional materials. We present a systematic application of tensor analysis and group theory to determine allowed physical-property tensors, vibrational-mode symmetries, and Raman selection rules directly from crystallographic point-group symmetry. The approach is applied to the prototypical ferroelectric PbZrxTi1-xO3 (PZT). Symmetry lowering across the PZT phase diagram increases the number of independent pyroelectric, dielectric, and piezoelectric tensor components and modifies the symmetry classification of Raman-active vibrations. These mode classifications enable symmetry-based decomposition of reported room-temperature powder Raman spectra as a function of composition (x) across the morphotropic phase boundary, revealing the tetragonal-to-rhombohedral transition as a continuous redistribution of spectral intensity rather than emergence of new Raman modes. Persistent subpeak structure in selected modes indicates local symmetry breaking due to cation disorder and lattice anharmonicity, underscoring the importance of crystallographic symmetry analysis for interpreting functional and vibrational properties of ferroelectric perovskite oxides.
Comments19 pages, 5 figures
Journal refThis article is under review in Phase Transitions journal in July, 2026, published by Taylor & Francis
