Hyperfine magnetic field at Cd impurity site in Clb Heusler alloys PtMnSb and NiMnSb by TDPAC technique

Abstract

The Time Differential Perturbed Angular Correlation (TDPAC) technique has been used to measure the temperature dependence of the hyperfine magnetic field (hmf) at the site of cadmium impurity in Clb Heusler alloys PtMnSb (Tc=575 K) and NiMnSb (Tc=720 K). Serving as probe was the 84-nsec 247-keV state of Cd-111, populated in the decay of 2.8-d In-111. Alloys were prepared by substituting for 2 atomic % of Sb by In metal which had been bombarded with 30-MeV protons to produce the In-111 activity. The measured hmf’s in kG at the Cd impurity, presumed to be at the Sb site, are (with temperatures in parentheses) in PtMnSb 166±4 (77 K), 153±2 (200 K), 138±2 (293 K), 125±2 (373 K), 95±2 (473 K), and 76±2 (488 K); in NiMnSb 213±3 (77 K), 208±4 (200 K), 194±3 (293 K), 191±4 (404 K), 169±4 (519 K), and 125±4 (630 K).