A SIMPLE FORMULA FOR THE THICKNESS CORRECTION OF SYMMETRICAL MOSSBAUER DOUBLETS - APPLICATION TO SPIN CROSS-OVER SYSTEMS

We have calculated the Mossbauer absorption integral for symmetrical quadrupole doublets as a function of the effective thickness T of the sample and of the ratio QS/GAMMA (quadrupole splitting/natural width); the resulting absorption A can be well approximated by a simple expression A approximately T/(1 + alpha-T), where alpha is a function of the resolution QS/GAMMA of the absorption lines. A convenient analytical expression is given for alpha(QS/GAMMA). As an example, the thermal variation of the absorption area of a spin cross-over system is analysed.