Thermophysics of the lanthanide trihydroxides II. Heat capacities from 10 to 350 K of Nd(OH)3 and Tb(OH)3. Lattice and Schottky contributions

Heat capacities have been measured from near 7 to 350 K for Nd(OH)3 and Tb(OH)3 and the derived thermophysical properties evaluated using previously reported heat capacities at lower temperatures. At 298.15 K the values of Cp/R, So/R, and -{Gc - Ho(0)}/RT are 14.15, 15.62, and 7.484 for Nd(OH)3 and 13.72, 15.44, and 7.525 for Tb(OH)3. The resolution of the lattice and Schottky contributions for both compounds is discussed. The Tb(OH)3 calorimetric Schottky contribution is correlated with spectroscopically deduced energy levels for Tb(OH)3 and Tb3+ -doped Y(OH)3, while that of Nd(OH)3 is used to estimate the crystal-field splitting of the 4I9/2 J-manifold. The effect of temperature upon the Schottky heat capacities is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23403/1/0000348.pd