Raman and x-ray study of La1-xNdxGaO3 (0≤x≤1) perovskite solid solutions

La and Nd gallates are currently being used as substrate materials for high temperature superconductor thin film deposition. In this work we have synthesized and characterized by means of XRD and Raman spectroscopy solid solutions of the type La1-xNdxGaO3 (0 less than or equal to x less than or equal to 1). Polarized Raman study of LaGaO3 and NdGaO3 single crystals is also performed. Our results confirm the Pbnm space group for both La and Nd perovskites at room temperature and the centrosymmetric R (3) over bar c for LaGaO3 in the high temperature phase. The orthorhombic to rhombohedral first order phase transition (T-c = 423 K in LaGaO3) is studied as a function of Nd substitution. T-c increases quadratically with x for x less than or equal to 0.14. Beyond x = 0.17 the phase transition, if present, is above the limit of our experimental setup (870 K). The detection of a soft A(1g) mode in the rhombohedral phase is interpreted as due to the existence of a virtual second order transition to cubic symmetry at high temperature, analogous to that observed in rare earth aluminates.