FRUSTRATED SPIN-GLASS-LIKE FEATURES IN KMNFEF6 SYSTEM

We report the experimental results of low field ac susceptibility, de magnetisation, Mossbauer data of the sample KMnFeF6. We observed that the system undergoes para to ferrimagnetic transition at T(N) (onset) approximately 148 K followed by a low temperature spin-glass like tran sition at approximately 108 K. There is no evidence of long-gauge magn etic order in the ferrimagnetic region. The interest in the material s tems from the fact that the existence of triangular platelets of the m agnetic ions (Kagome like lattice) are accompanied by the square plate lets. The geometrically frustrated triangular lattice, statistically o ccupied by the Mn2+/Fe3+ ions with strong AFM interactions seems to be the origin of this SG like state. We believe that the present observa tion of the SG like-transition in this system where he triangular latt ice coexists with square lattice, is the first of its kind to our know ledge.