Temperature dependence of the quadrupole interaction of⁶⁹GeTl and¹¹³SnSn

Abstract

The quadrupole interaction constants of⁶⁹GeT1 and¹¹³SnSn were measured by means of the perturbed angular distribution technique as a function of temperature in the range of 80K≦T≦508 K and 80K≦T≦480 K, respectively. Isomeric states in⁶⁹Ge and¹¹³Sn were populated by the heavy ion reactions⁵⁶Fe(¹⁶O, 2p n) and¹⁰⁰Mo(¹⁶O, 3n) and recoil implanted into polycrystalline Tl- and single crystalline Sn-backings. In the case of¹¹³SnSn, where the quadrupole coupling is weak, a special single crystal geometry was employed to enhance the sensitivity of the measurement. Within the limits of the errors the temperature dependence for both systems follows the empirical T^1.5-dependence. While a strong temperature dependence comparable to InIn is observed for⁶⁹GeT1, that for¹¹³SnSn is weaker than expected. The strength of the temperature dependence for¹¹³SnSn does not agree with the predictions of a lattice vibration model proposed recently for the temperature dependence of the quadrupole interaction.