High field ESR studies of spin gap systems F2PNNNO and KCuCl3 have been performed. The broadening of the linewidth in F 2PNNNO is observed near the start of the 1/2 plateau but not near the entrance of the field induced order at 9 T. The possible origin is discussed. The reduction of the spin gap by pressure in KCuCl3 is observed directly by high field ESR under pressure. The result is discussed in connection with the theory by Matsumoto et al.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)