Inherent properties of complex structured solids

In this paper, we present two empirical expressions relating the lattice thermal conductivity (K in mW cm K-1) and bulk modulus (B in Gpa) for the chalcopyrite (A(I)B(III)C(2)(VI) and A(II)B(IV)C(2)(V)) semiconductors. The lattice thermal conductivity of these compounds exhibit a linear relationship when plotted on a log-log scale against the nearest-neighbour distance d (angstrom), but fall on different straight lines according to the ionic charge product of the compounds. On the basis of this result a simple bulk modulus-lattice thermal conductivity relationship is proposed and used to estimate the bulk modulus of A(I)B(III)C(2)VI and A(II)B(IV)C(2)(V) semiconductors. We have applied the proposed relations on these semiconductors and found a better agreement with experimental data as compared to the values evaluated by earlier researchers. The results for lattice thermal conductivity (K) differ from experimental by CuAlTe2 (6.1%), CuGaSe2 (2.4%), CuGaTe2 (11%), CuInTe2 (4%), ZnSiAs2 (12%), ZnGeAs2 (1.7%), CdGeP2 (5.5%) and the results for bulk modulus differ from experimental by CuAlS2 (1%), CuGaS2 (1%), CuGaSe2 (7%), AgGaS2 (1.5%), CdSiP2 (5.2%) and CdGeAs2 (4.3%).