Crystal structures and phase transitions in the SrTiO3-SrZrO3 solid solution

Laboratory and synchrotron X-ray powder diffraction and neutron powder diff raction have been used to determine crystal structures in the perovskites S rTixZr1-xO3. Superlattice reflections in the neutron diffraction patterns p roved to be the most reliable indicators of lower symmetry structures. The room temperature structures are orthorhombic Pbnm in the range of 0 less th an or equal to x less than or equal to 0.4, tetragonal I4/mcm in the range 0.4 < x <less than or equal to> 0.95, and cubic Pm (3) over barm for 0.95 < x <less than or equal to> 1. Additional measurements were made on the room -temperature tetragonal samples at x = 0.5, 0.75, and 0.9, The first two we re examined at elevated temperatures, using neutron diffraction methods, wh ere the transition tetragonal to cubic was noted. Measurements at low tempe ratures using synchrotron X-ray powder diffraction are reported. (C) 2001 A cademic Press.