PHONON DENSITY OF STATES OF EUROPIUM SELENIDE UNDER

Abstract

A remarkable feature observed in EuSe is that, it exhibits various magnetic phases with changing temperature; it is antiferromagnet II at temperature between 0-1.8K, ferri between 1.8-2.8 K and antiferromagnetic I between 2.8-4.6 K. Such magnetic behavior in EuSe is attributed to the change in lattice constant. Thus application of pressure to this compound can be very interesting through the decrease in lattice constant.  In the present investigation  one phonon density  of states of Europium selenide have been calculated under  pressure  by using a simple  lattice  dynamical theory  namely  the three body force rigid ion model (TRIM) which includes long range three  body  interactions arising  due to  charge transfer effects. We have  observed a pronounced shift  in phonon  spectrum  to the  higher  frequency  side  as  pressure  is increased.