Proc. of the Yamada Conf. VII, Muon Spin Rotation, Shimoda, 1983 Hyperfine Interactions 17-19 (1984) 387-392 POSITIVE MUONS IN ANTIMONY BISMUTH ALLOYS F.N. GYGAX, A. HINTERMANN, A, SCHENCK, W. STUDER, and A.J. VAN DER WAL Institute for Medium Energy Physics, ETH Zarich, S.I.N., CH-5234 Villigen, Switzerland J.H. BREWER, D.R. HARSHMAN, E. KOSTER, H. SCHILLING*, and D.L1. WILLIAMS Department of Physics, University of British Columbia Vancouver, B.C., Canada V6T2A3 and M.G. PRIESTLEY H.H. Wells Physical Laboratories, University of Bristol Bristol, England Received 18 April 1983 Stroboscopic #SR and TD-#SR techniques were used to measure the #+ Knight shift Kv and relaxation rate A in SbBi alloys as functions of magnetic field H, temperature T, the angle 0 between H and the crystalline ~ axis, and the concentration [Bi] of alloyed Bi. In pure Sb and in SbBi (6.5%), K v (0 = 0) and/~ (0 = ~r/2) both decrease linearly with Tup to about 100 K, but both K, and its anisotropy are smaller in the 6.5% alloy, indicating a "dilution" effect. With 15 at .% Bi,/~ is reduced further but its T-dependence and that of A are dramatically altered. At low temperatures Ku (0 = 0) in SbBi(15%) actually becomes negative and the sign of the anisotropy is reversed. In the same sample, A is proportional to H at both 20 K and 150 K; at 120 K A is proportional to/~ if 0 is used as an implicit variable, but at 36 K this is not the case. A consistent phenomenological description is offered. Knight shifts supposedly depend on the bulk electronic structure of the host metal only through the magnetic susceptibility of the conduction electrons. [1] However, recent measurements of the positive muon Knight shift K~ in Cd [2] suggest that subtle features of the host band structure may be manifest as well. This was in retrospect implied by earlier observations [3] of an abnormally large K~ (~ 100 times as large as found in most metals) in the weakly diamagnetic semimetal an- timony (Sb). In an effort to better understand the role of the band structure in this * Present address: Im Stocker 29, CH-8405 Winterthur, Switzerland. J.C. Baltzer AG, Scientific Publishing Company, and Yamada Science Foundation