  Nonlinear characteristic emissions of K alpha, K beta and gamma with a
significant triplet splitting at room temperature are observed from the
long-lived nuclear state of 103mRh excited by bremsstrahlung irradiation. A
pronounced phase-transition-like narrowing of the emission profiles occurs
immediately after the sample is cooled down to 77 K. The room temperature
profiles reappear again abruptly and almost reversibly as the temperature
drifts freely back to approximately the ice point after the filling of liquid
nitrogen is stopped. These emission properties at 300 K and at low temperature
may indicate that the 103mRh nuclei are in collective states.
