Pressure Variation of Mössbauer Fraction for an Impurity Atom

Abstract

The variation of "Mossbauer fraction" ,/,with pressure of Fe5' embedded as a dilute in]-purity in Ti, V, Ni, Cu, Mo, Pd, W, and Pt host lattices has been calculated by incorporating bothithe force constant change and the mass change a t the site of the impurity. Comparison of the calculations with available experimental values of the slope gives definite evidence for the change of the force constant q'/q. The value of q'/q thus obtained is in agreement with that obtained from the variation o f f with temperature for Fe in Cu, but not for Fe in V.Die Andernng von ,,Mossbauer fraction",f, mit dem Druck wurde durch Einbeziehung sowohl von Anderungen der Kraftkonstante als auch von Massenanderungen am Defektplatz fur FeS7, das als verdunnte Verunreinigung in Ti-, V-, Ni-, Cu-, Mo-Pd-, W-und PtWirtsgittern eingebaut war, berechnet. Ein Vergleich der Rechnungen mit erhaltlichen experimentellen Werten ergibt einen definitiven Beweis fur die A n F u n g der Kraftkonstante q'/q. Der so erhaltene Wert von q'/q befindet sich mit dem in obereinstimmung, der a m der Temperaturiinderung von f fur Fe in Cu, nicht aber fur Fe in V erhalten wurde.

On the Usability of Debye Theory in Mössbauer Spectroscopic Studies

“…This value of Oeff, when substituted in (13), gives (,YIP) = 1.88. This is in agreement with that obtained by Nandwani and Puri [6]. What is more that our approach outlined above is free from any arbitrary parameterisation of the Debye temperature.…”

Pressure Dependence of Mossbauer Fraction and Energy Shift for Fe6' in Cu Lattice at 298 and 94 °K

“…for Fe67 impurity in Cu [ l to 31, Mo [5], and Pt [6, 71 hosts, (q'/q) = 1.2; 0.45 and 0.70 respectively. Similar conclusions for q'/q change were obtained by the present authors for the first time, from the analysis of pressure variation o f f for Fe5' impurity in Cu and V [3].…”

On the Pressure Dependence of the Debye Temperature in Solids

“…The knowledge of the pressure dependence of the Debye temperature q is needed for studying the recoilless fraction of g-ray emission or absorption in the Mo È ssbauer effect, especially to account for the effect of an impurity in host materials [1,2]. In view of that q is related to the Gru È neisen parameter g by the following relation:…”

“…With the help of (2) and (3) Kumari and Dass obtained the relation for the pressure dependence of q as follows:…”