Probing magnetic fields on crystals of the nanomagnet Mn12-acetate by electron paramagnetic resonance.

摘要: Abstract We report on electron paramagnetic resonance (EPR) probing of magnetic fields and field gradients near the surface a single crystal nanomagnet [Mn 12 O (CH 3 COO) 16 (H 2 O) 4 ] · 2CH COOH · 4H (Mn -Ac). As EPR probe, we utilized 0.7 mm × 30 μm × 30 μm fiberous needle organic conductor N -methylphenazinium-tetracyanoquinodimethane (NMP-TCNQ), which yields an exceptionally sharp peak, with 0.2 G (∼20 μT) width. In presence Mn -Ac, probe’s peak exhibits splitting temperature lowering, depends orientation Zeeman relative to axis easy magnetization employed -Ac crystal. The shifted peaks yield magnitude from various fibers probe are subjected. conjunction microscopy, shifts gradient at its change temperature. For 10 K, was measured be in mT range order 50 T/m.