Abstract
Satellite-transition magic angle spinning (STMAS) is a recently introduced technique for recording high-resolution NMR spectra of quadrupolar nuclei in solids. We present numerical calculations of STMAS signal intensity as a function of radiofrequency field strength (ν₁) and spinning rate (ν_R) and show that the sensitivity advantage of STMAS over the older multiple-quantum technique (MQMAS) is greatest for low ν₁ field strengths and high ν_R rates, making STMAS particularly suitable for the study of low-γ nuclei. The practical implementation of STMAS in NMR of low-&gamma nuclei is discussed and several experimental examples of high-resolution ³⁹K (I = 3/2) and ²⁵Mg (I = 5/2) NMR spectra are presented, including ²⁵Mg spectra of brucite (Mg(OH)₂), diopside (CaMgSi₂O₆) and talc (Mg₃Si₄O₁₀(OH)₂) recorded at the natural ²⁵Mg abundance of 10%.