Magnetization of polycrystalline ytterbium in the region of low-temperature structural transition

The temperature and magnetic field dependences of the magnetic moment $M(T,H)$ of polycrystalline ytterbium were studied in the region of phase transformation from a low-temperature close-packed hexagonal structure to a high-temperature face-centered cubic structure. The $M(T)$ dependences have paramagnetic form for both phases and are described by the Curie–Weiss law in the entire temperature range, except for $T\le10$ K. In the temperature range of the structural transformation $150$ $<T<$ 400 K, a hysteresis is observed in the $M(T)$ dependence, the form of hysteresis depends on the magnitude of the applied magnetic field. The hysteretic dependence $M(T)$ can be considered as a consequence of overcooling of the high-temperature phase of ytterbium with decreasing temperature and, accordingly, overheating of the low-temperature phase with increasing temperature. During slow cooling, a small fraction of the high-temperature phase is retained down to low temperatures $T\sim10$ K. The dependences of the magnetic moment on the magnetic field $M(H)$, for different branches of magnetic hysteresis, are linear up to $H = 140$ kOe. In low fields, a small addition of a ferromagnetic type is observed, probably associated with the presence of a magnetic impurity or with Yb$^{3+}$ ions localized near structural defects.