Temperature dependence of soft magnetic properties in amorphous Co69Fe4.5Cu1.5Si10B15 alloy

The temperature dependence of soft magnetic properties in amorphous ${\mathrm{Co}}_{69}{\mathrm{Fe}}_{\text{4.5}}{\mathrm{Cu}}_{\text{1.5}}{\mathrm{Si}}_{10}{\mathrm{B}}_{15}$ alloy was investigated by the changes of incremental permeability ratio (PR) and magnetoimpedance ratio (MIR) as a function of temperature from 10 to 300 K. The temperature dependence of PR and MIR is directly related to the temperature dependence of soft magnetic properties. The soft magnetic properties in ${\mathrm{Co}}_{69}{\mathrm{Fe}}_{\text{4.5}}{\mathrm{Cu}}_{\text{1.5}}{\mathrm{Si}}_{10}{\mathrm{B}}_{15}$ alloy annealed at 400 °C are very stable for temperature variation at low temperature. The spin wave stiffness constant, D, was estimated from the temperature dependence of the magnetization at low temperature.