The micro-structures and vibrational modes of complex double perovskite oxides xLaAlO3 – (1-x)Ba(Mg1/2 W1/2 )O3[LABMW] have been characterized for different values of x (0.10, 0.25, 0.50, 0.75 and 0.90). The materials are synthesized by the solid state reaction technique. The Rietveld refinement of the XRD patterns shows rhombohedral R3􀴤C(161) phase for LaAlO3 and cubic Fm3m (225) phases for Ba(Mg1/2W1/2)O3. XRD patterns show that with increasing the doping concentration ‘x’, rhombohedral phase gradually increases and cubic phase gradually decreases. A meticulous comparison of crystal structures and vibrational degrees of freedom in the light of change in doping concentration ‘x’ for LA-BMW has been carried out for accurate identification of crystal symmetry and distortions. From room-temperature comparative Raman spectra of the samples, different vibrational phonon modes have been assigned using group theoretical analysis together with experimental literature survey.

中文翻译：

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复合双钙钛矿氧化物 xLaAlO3 – (1-x)Ba(Mg1/2 W1/2 )O3 的微观结构和振动模式

复合双钙钛矿氧化物 xLaAlO3 – (1-x)Ba(Mg1/2 W1/2 )O3[LABMW] 的微观结构和振动模式已表征为不同的 x (0.10, 0.25, 0.50, 0.75 和 0.90 ）。该材料是通过固态反应技术合成的。XRD 图的 Rietveld 细化显示，LaAlO3 为菱形 R3􀴤C(161) 相，Ba(Mg1/2W1/2)O3 为立方 Fm3m (225) 相。XRD图谱表明，随着掺杂浓度'x'的增加，菱形相逐渐增加，立方相逐渐减少。根据 LA-BMW 掺杂浓度“x”的变化，对晶体结构和振动自由度进行了细致的比较，以准确识别晶体对称性和畸变。从样品的室温比较拉曼光谱，