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

Growth of single crystals in the pseudobinary LaGaO3-NdGaO3 system by the Czochralski method was investigated. It was found that solid solution crystals La1 - xNdxGaO3 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 LaGaO3 at 150 degrees C rises linearly with Nd concentration at the rate of 20.5 degrees C/Nd mol% up to the melting temperature. The segregation coefficients of Nd in LaGaO3 and La in NdGaO3 have been found to be k(eff)(Nd) approximate to 0.77 and k(eff)(La) approximate to 1.3. (C) 2000 Published by Elsevier Science B.V. All rights reserved. PACS. 81.10. - h; 81.10.Fq; 68.35.Bs.