Magnetostriction of First and Second Order Magnetite Samples and its Relation to the Magnetic Easy Axis Switching
Magnetic field (up to 8T) and temperature (10-300K) dependence of size of Zn doped magnetite samples Fe3-xZnxO4 (x=0.008, 0.022, i.e. falling within first and second order Verwey transition regime) were measured by the strain gauge method. Both samples experienced shrinking on cooling through the Verwey transition along monoclinic c axis, while the strong expansion was found for the 1st order sample in the a-b direction, unlike in the 2nd order sample. Magnetostriction of both samples is very small and limited to low fields only, concomitant with magnetization process. However, field application perpendicular to c axis and at T slightly below the Verwey transition temperature TV results in a large change of dimensions, coinciding with the axis switching process.
Yuriy Verbovytskyy and António Pereira Gonçalves
A. Britwum et al., "Magnetostriction of First and Second Order Magnetite Samples and its Relation to the Magnetic Easy Axis Switching", Solid State Phenomena, Vol. 194, pp. 120-123, 2013