MUONIUM IN ULTRA-PURE GERMANIUM.

The spin precession signals of positive muons ( mu ** plus ) implanted into Ge single crystals of ultra-high purity (electronically active impurity concentration APP 1STH 3. 10**1**1 cm** minus **3) containing between 10**1**2cm** minus **3 and 10**1**7cm** minus **3 Si were investigated at temperatures ranging from 5K to 280K in magnetic fields of 0. 3 mT to 27. 5 mT applied perpendicular to the mu plus polarization. As in previous work, the spin precession of muons in diamagnetic environments left bracket ″mu plus″ right bracket and of normal ( ″isotropic″ ) muonium left bracket Mu equals ( mu ** plus e** minus ) right bracket as well as of anomalous ( ″anisotropic″ ) muonium left bracket Mu* right bracket were observed. The damping of the Mu signal increases drastically with increasing Si content. This indicates that the muonium diffuses rather rapidly through the Ge matrix and interacts with solute Si atoms.