Orientation dependence of elastic and piezomagnetic properties in NiFe2O4

In this paper, the crystal orientation dependence of the elastic and piezomagnetic properties have been calculated for nickel ferrite (NiFe2O4) in three-dimensional space by means of coordinate transformations. The maximum elastic compliances s11′, s12′ and piezomagnetic constants q31′, q33′ along specific orientations have been determined based on experimental data of NiFe2O4 and original matrices for m3m point group. The piezomagnetic constants q31′ and q33′ show highly dependence on crystal orientation compared with elastic compliances s11′, s12′, meanwhile permittivity μ33′ is a constant. The max s11′ and s12′ can be obtained along directions [n k l] (n·k = 0, l ≠ 0) and [n k l] (n·k·l = 0), respectively. The max q31′ and max q33′ lie along [0 0 1] and [1 1 1] axes, respectively, NiFe2O4||[1 1 1] axis can produce large q31′ and q33′ at the same time. The result suggests that by adopting the optimal directions, the elastic and piezomagnetic properties of the devices made from NiFe2O4 can be precisely modulated.