Petrov Dimitar
Acta Chim Slov. 2014;61(1):34-8.
Lattice energies ΔLHθ of lanthanide orthophosphates, LnPO4 (Ln=Ce-Lu, excluding Pm) have been determined from the Born-Haber cycle and compared with those calculated by other methods. The Born-Haber cycle results in close values of ΔLHθ to those obtained after an empirical equation proposed by Glasser and Jenkins. It has been found that: (i) the partial derivative of the lattice enthalpies to the molar volumes corresponds by dimension and magnitude to the shear moduli of these crystals; (ii) these moduli differ for the monazite- and xenotime-type structures of LnPO4. Molar polarizabilities have been calculated for three LnPO4 with monazite structure, Ln=Ce, Nd, Sm, and for three LnPO4 with xenotime structure, Ln=Tb, Dy, Yb.
通过玻恩-哈伯循环测定了镧系正磷酸盐LnPO₄（Ln = Ce - Lu，不包括Pm）的晶格能ΔLHθ，并与其他方法计算得到的结果进行了比较。玻恩-哈伯循环得到的ΔLHθ值与根据格拉瑟和詹金斯提出的经验方程得到的值相近。研究发现：（i）晶格焓对摩尔体积的偏导数在量纲和大小上与这些晶体的剪切模量相对应；（ii）LnPO₄的独居石型和磷钇矿型结构的这些模量不同。计算了三种具有独居石结构的LnPO₄（Ln = Ce、Nd、Sm）以及三种具有磷钇矿结构的LnPO₄（Ln = Tb、Dy、Yb）的摩尔极化率。
