Evidence of low temperature spin glass transition in bixbyite type FeMnO3

Abstract : We report the solution combustion synthesis of FeMnO3 as well as its detailed structural and magnetic characterizations. The X-ray and electron diffraction studies were utilized for structural characterization. It crystallizes in cubic Ia3 space group with bixbyite structure having cell parameter a = 9.413(4) angstrom. It is observed that FeMnO3 lacks long range ordering and shows spin glass behaviour with a freezing temperature T-g similar to 33 K. This result is in contradiction with the earlier reports of long range antiferromagnetic and ferrimagnetic ordering. The prevalence of spin glass state has been explained with the most relevant dynamic scaling theory giving the glass transition, critical exponent and characteristic time, respectively, T-g = 33 +/- 0.2 K, zv = 5.7 +/- 0.5 and tau(0) similar to 10(-12) s. The evolution of spin glass state can be ascribed to the structural genesis, where the competing antiferromagnetic and ferromagnetic interaction as well as cationic disordering results in magnetic frustration.