Abstract
The temperature dependence of the EPR linewidth in single crystal MnS and MnO have been measured at 35 GHz. The EPR in MnS abruptly stops at 152°±0.5°K as the temperature is decreased. The linewidth in MnS is proportional to (T‐TN)−3/8 for 1° ≤ (T‐TN) ≤ 6°K. In both MnS and MnO the linewidth is proportional to T/(T‐TN) for T‐TN > 10°K. In this high‐temperature region the constants of proportionality are 80 and 280 Oe, respectively. An applied field of 12 500 Oe does not shift the Néel temperature in MnS.