Scalar and anisotropicJinteractions in undoped InP: A triple-resonance NMR study

The heteronuclear J-coupling tensor between nearest neighbor ³¹P and ¹¹³In spins in undoped InP is investigated by means of ¹¹³→In³¹P polarization transfer under rapid magic angle spinning (MAS). The scalar contribution can be measured directly and is found to have the value |Jⁱˢᵒ(³¹P-113,115In)|=(225±10) Hz. The principal value of the traceless anisotropic J-coupling tensor (pseudodipolar coupling) is determined to be ${J}ᵃⁿⁱˢᵒ{(}³¹P{{-}}113,115In)=2/3[{J}_{{}}{(}³¹P{{-}}113,115In){-}{J}_{{⊥}}{(}³¹P{{-}}113,115In)]=(813±{}50) $ or $(1733±{}50) Hz,$ assuming axial symmetry with the principal axis parallel to the In-P bond. Our values deviate from those reported previously [M. Engelsberg and R. E. Norberg, Phys. Rev. B 5, 3395 (1972)] [based on a moment analysis of the ³¹P resonance |Jⁱˢᵒ(³¹P-113,115In)|=350 Hz and Jᵃⁿⁱˢᵒ(³¹P-113,115In)=1273 Hz], but confirm the postulate that the nearest neighbor ³¹P-113,115In magnetic dipolar and pseudodipolar interactions are of the same order of magnitude and partially cancel each other.