Crystal growth and physical properties of La2-2xSr1+2xMn2O7

Single crystals of La2-2xSr1+2xMn2O7 (x = 0.4) were grown by a floating zon e method by using a starting rod sintered at optimized temperature. The gro wn crystal was characterized to be a high-quality one through the X-ray and resistivity measurements. The longitudinal and transverse sound velocity h as been measured for this compound as a function of temperature. Elastic co nstants c(33) and c(44) show hardening behavior below T-c. The constant c(4 4) shows a small softening near T-c. (C) 2000 Elsevier Science B.V. All rig hts reserved.