Microhardness-bulk modulus scaling and pressure-induced phase transformations in A(I)B(III)C(2)(VI) chalcopyrite compounds

The microhardness H of the A(I)B(III)C(2)(VI) chalcopyrites can be estimate d from the bulk modulus B-0 by using a simple scaling law. Values of B-0 fo r these compounds, obtained from energy dispersive x-ray diffraction and x- ray absorption spectroscopy techniques under high pressure, have been used in the scaling. The pressure-induced phase transformation from the chalcopy rite to denser structures, observed in these compounds, is also discussed. A relationship between H and the critical pressure at which such a transiti on occurs is also obtained. (C) 1999 American Institute of Physics. [S0021- 8979(99)05216-0].