低温下六方晶格的固体热容与德拜模型比较

Comparison between hexagonal prism’s specific heat and Debye model at low temperature

根据晶格动力学方程 ,求解镧等六方晶格的晶格振动问题 ,在具体方向上得到了晶格色散关系 ,进而得到了态密度表达式 ,并计算出低温下热容 .结果表明与德拜模型一样只与T3成正比 .通过与低温下德拜热容比较 ,确定出力常数表达式 ,进而得到镧的力常数为 9.838N/m .

By using the equation of crystal dynamics, we present a resolving process of hexagohal prim crystal vibration. Then crystal dispersion function on special direction is shown. On the basis of it, the state density is obtained. At last, we calculate their specific heat at low temperature and find them proportional to T 3. Through comparing two special heat expression, force constant can be defined. For example La's force constant is 9.838?N/m.