Strong temperature-dependent thermoelectric power of IrMn₃ thin films of different thicknesses

IrMn₃ thin films were experimentally characterized by thermoelectric power and resistivity as a function of temperature and sample thickness. The Seebeck coefficient shows strong temperature dependence and the value increases with temperature up to 350 K. An empirical Boltzmann sigmoid function can fit our data remarkably well. The temperature-dependent resistivity shows a similar behavior as the thermoelectric power, i.e. both these two properties exhibit a transitional behavior at some critical temperature range, which is further confirmed by the magnetic susceptibility measurements. (letter)