TEMPERATURE DEPENDENCE OF FORCED MAGNETOSTRICTION OF NICKEL

Forced longitudinal and transverse magnetostrictions for polycrystalline Ni have been measured by strain gauge technique at temperatures from 200 to 613°K below the Curie point. Results obtained show clearly an anisotropy, so that the forced volume magnetostriction is turned out not to be equal to three times as large as the forced longitudinal magnetstriction. The temperature dependence of the forced volume magnetostriction obtained reliably shows to be positive below T/Tc≅0.7 and negative above it. The forced volume magnetostriction at 0°K, (∂ ω/∂ H)0=1.4×10 -10Oe-1, and the change of the Curie point with pressure, ∂ Tc/∂ p =3.2×10-4 deg/bar, are estimated thermodynamically and agree with Kondorsky's results and with Patrick's, respectively. A special attension is given to an anomalous thermal expansion near the Curie point. © 1969, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.