Magnetization of the Mn$_{1-x}$Fe$_x$Si in high magnetic field up to 50   T: possible evidence of a field-induced Griffiths phase
  Magnetic properties of single crystals of Mn$_{1-x}$Fe$_x$Si solid solutions with $x < 0.2$ are investigated by pulsed field technique in magnetic fields up to 50 T. It is shown that magnetization of Mn$_{1-x}$Fe$_x$Si in the paramagnetic phase follows power law $M(B) \sim B^\alpha$ with the exponents $\alpha \sim 0.33-0.5$, which starts above characteristic fields $B_c \sim 1.5-7$ T depending on the sample composition and lasts up to highest used magnetic field. Analysis of magnetization data including SQUID measurements in magnetic fields below 5 T suggests that this anomalous behavior may be likely attributed to the formation of a field-induced Griffiths phase in the presence of spin-polaron effects. 
S.V. Demishev, A.N. Samarin, J. Huang, V.V. Glushkov, I.I. Lobanova,   N.E. Sluchanko, N.M. Chubova, V.A. Dyadkin, S.V. Grig...
cond-mat.str-el