Magnetic properties of BiFeO3 micro-cubes synthesized by microwave   agitation
  In this report we present results of magnetization measurements and investigation of aging and memory effect in bismuth ferrite multiferroic micro-cubes obtained by means of simple microwave synthesis procedure. It is found that difference between FC and ZFC magnetizations appears at the temperature of freezing of ferromagnetic domain walls. The decay of the magnetic moment vs. time described by power-law relation and the absence of memory effect indicate domain growth mechanism rather than the spin-glass phase. 
B. Andrzejewski, K. Chybczynska, K. Pogorzelec-Glaser, B. Hilczer, B.   Leska, R. Pankiewicz, P. Cieluch
cond-mat.mtrl-sci cond-mat.other