Magnetic properties of Pd doped with Fe: Intermediate between ferromagnetism and spinglass behavior

Abstract

The electrical impedance, the ac susceptibility, and the ad magnetization of Pd doped with Fe, whose concentration is between the one for ferromagnetic order and spinglass behaviour, were investigated in the temperature range from 2 mK to 4K and at 0.3μT ≲ H ⩽2 mT. This Fe concentration is between the one for spin glass freezing and the one for ferromagnetic order. With the ac susceptibility and the dc magnetization data, we can exclude a ferromagnetic transition or a reentrant magnetic phase transition. The ac susceptibility, measured directly as well as extracted from the imaginary part of the ac impedance, shows magnetic clustering followed by spin glass (spincluster glass) freezing at 50 mK. The resistivity, obtained from the real part of the ac impedance, exhibits a very complicated temperature dependence which can be understood in terms of spin fluctuations, magnetic clustering, and electron-magnon scattering inside of the magnetic clusters.