Large Spontaneous Volume Magnetostriction of Mn-Rh Alloys

The differential scanning calorimetry (DSC) curves and the temperature dependence of magnetic susceptibility for [Gamma]-MnRh ordered alloys show a marked peak associated with the magnetic transition. The Neel temperature of [Mn.sub.7] [sub.7][Rh.sub.2 3] and [Mn.sub.7] [sub.5][Rh.sub.2 5] ordered alloys is determined to be about 830 and 850 K, respectively. The paramagnetic susceptibility increases with increasing temperature, showing an itinerant electron characteristics. The thermal expansion coefficient becomes small below the Neel temperature due to a large spontaneous volume magnetostriction, taking about 5x1 [0.sup.-6]/K around room temperature. Such alloys with a small thermal expansion coefficient would induce some strain in multilayers because of the difference between the thermal expansion. Index Terms - Antiferromagnetic [Gamma] -Mn alloy, itinerant electron characteristics, Neel temperature, thermal expansion, volume magnetostriction.