Czochralski growth and structural investigations of La1−xNdxGaO3 solid solution single crystals

Abstract Growth of single crystals in the pseudobinary LaGaO 3 –NdGaO 3 system by the Czochralski method was investigated. It was found that solid solution crystals La 1− x Nd x GaO 3 exist in the whole concentration range. The structure of the crystals was investigated by X-ray diffraction method. It was found that the unit cell volume decreases linearly with increasing Nd concentration in agreement with Vegard's law. With increasing Nd concentration x the lattice parameters a and c decrease, whereas b increases. At x =0.32 parameters a and b become equal and the crystal adopts the pseudo-tetragonal structure. The differential thermal analysis proved that the temperature of the first-order phase transition observed in LaGaO 3 at 150°C rises linearly with Nd concentration at the rate of 20.5°C/Nd mol% up to the melting temperature. The segregation coefficients of Nd in LaGaO 3 and La in NdGaO 3 have been found to be k eff (Nd)≈0.77 and k eff (La)≈1.3.