Co-Ferrite: a material with high magnetostriction produced by different methods

摘要

Polycrystalline Co-ferrite was produced using different routes such as: ball milling, modified citrate-gel method, fluoride modified citrate-gel method and combustion method. All samples were afterward heat treated. The XRD pattern shows that all samples (except that produced by fluoride modified citrate-gel method) exhibit a single phase spinel structure. Measurements of hysteresis loops demonstrate that after the heat treatment a saturation magnetization of 81 - 83 emu/g is obtained, which is typical for single phase CoFe_(2)O_(4). Measurements of the longitudinal magnetostriction gave values between 110 and 126 ppm. Only the sample produced by the combustion method behaves different: it exhibits a smaller lattice constant, a lower magnetization and a lower magnetostriction (about 30 ppm). The for application important strain derivative d(lambda)/dH was highest for the sample produced by modified citrate-gel method with a value of d(lambda)/dH velence 639 ppm/T velence 8.10~(-10)A~(-1)m followed by the ball milled material heat treated at 1000 deg C for 24 h with a value of d(lambda)/dH velence 581 ppm/T velence 7.3.10~(-10)A~(-1)m.