NUCLEAR RESONANCE ABSORPTION AND NUCLEAR ZEEMAN EFFECT IN Fe$sup 5$$sup 7$

Nuclear resonance absorption in Fe/sup 57/ was measured at an angle theta = 30 deg as a function of temperature. Zeeman splitting was observed in the resonance absorption curve not corrected for absorber thickness or finite velcoity resolution and is considered due to the interaction of the magnetic moment mu * of the excited state with the magnetic field H at the nucleus. The magnetic moment of the excited state was estimated to be mu * = 0.50 mu /sub n/. The measured width of the central line, 2 GAMMA = 3.4 x 10/sup -6/ ev, was larger than the predicted value. (C.J.G.)