Magnetic, magnetoelastic, and spectroscopic properties of TmAl3(BO3)4

The thermodynamic properties of alumoborate TmAl3(BO3)4 single crystal are studied experimentally and theoretically. A theoretical analysis based on the crystal field model makes it possible to interpret all measured parameters. The crystal field parameters are determined. The temperature (3–300 K) and field (up to 9 T) dependences of magnetization are described. The field and temperature dependences of multipole moments of the Tm3+ ion in TmAl3(BO3)4 make it possible to describe magnetostriction and low-temperature anomalies in thermal expansion.