Growth, mechanical, and magnetic study of SmFeO3 single crystal grown by optical floating zone technique

Single crystals of Samarium orthoferrite (SmFeO3) have been grown by the optical floating zone technique. The growth parameters to yield good quality crystals are 5 mm/h for pulling and 30-40 rpm for rotation. The mechanical behavior of the grown crystal has been investigated. Rosette pattern has been observed around the indentation and the microhardness has been found to decreases non-linearly with the applied load. For load higher than 1.96 N there is a transition from palmqvist to median crack due to plastic deformation of the crystal. The hardness parameters like fracture toughness, brittleness index, and yield strength have also been calculated for palmqvist and median cracks occurring on the crystal surface. The magnetic investigations revealed that a magnetic transition in the range of 300-180 K. Above 180 K, the magnetization decreases as Sm and Fe sublattices have opposite spins. At high temperature, two anomalies are observed, one due to near spin reorientation (T-SR = 480 K) and the other is AFM to paramagnetic transitions (T-N = 670 K). The MeH curves exhibit a shape change with temperature due to the emergence and enlargement of multi-domain state of the SmFeO3 crystals. Bloch parameter (3.28 x 10(-5) K-3/2) has also been evaluated. (C) 2016 Elsevier B.V. All rights reserved.