LATTICE HEAT-CAPACITY OF CRYSTALS - A Q-OSCILLATOR DEBYE MODEL

The Debye model for lattice heat capacity is modified retaining all th e basic assumptions except that each mode is here treated as a q-defor med quantum harmonic oscillator. The lattice heat capacity C(v) is eva luated in the high and low temperature limits. When T much less than t heta(D), C(v) is-proportional-to T3 and when T much greater than theta (D), C(v) is-proportional-to T2. In the case of the alkali elements Rb , Cs and K whose Debye temperatures are relatively low, the calculated values compare remarkably well with experimental results over a wide range of temperatures.