Pressure dependence of elastic constants for intermetallic compounds

Elastic properties of solids are closely related to many fundamental properties such as EOS, thermal expansion, interatomic potentials etc. The relatively strong covalent bonding between the constituents of intermetallic compounds like LiBC, MgB2 and TiB2 gives high Bulk Modulus in the range 150-220 GPa at high melting point nearly 3000K. This behaviour makes these compounds very interesting for studies under high pressure and high temperature. In the present study, pressure-volume relationship at different temperatures for three intermetallic compounds is given. For the low compressions the increase in pressure is low but the rate of increase of pressure increases faster as we approach the high compression region. At higher temperature, the bulk modulus decreases and, therefore, the pressure required for producing same amount of compression becomes less and less.