Nuclear magnetic resonance of 55 Mn in the antiferromagnet CsMnBr 3 in a variable longitudinal magnetic field

The spectrum and intensities of NMR lines are investigated experimentally and theoretically for excitation by an alternating magnetic field h ‖ parallel to a static field H in the quasi-one-dimensional, six-sublattice antiferromagnet CsMnBr 3 . According to theory, two new NMR lines, which are not excited by a transverse magnetic field h ⊥ , are observed near the phase transition from triangular to collinear structure ( H = H c ) [JETP 86 , 197 (1998)].