Mott versus Slater-type metal-insulator transition in Mn-substituted   Sr3Ru2O7
  We present a temperature-dependent x-ray absorption (XAS) and resonant elastic x-ray scattering (REXS) study of the metal-insulator transition (MIT) in Sr3(Ru1-xMnx)2O7. The XAS results reveal that the MIT drives the onset of local antiferromagnetic correlations around the Mn impurities, a precursor of the long-range antiferromagnetism detected by REXS at T_order<T_MIT. This establishes that the MIT is of the Mott-type (electronic correlations) as opposed to Slater-type (magnetic order). While this behavior is induced by Mn impurities, the (1/4,1/4,0) order exists for a wide range of Mn concentrations, and points to an inherent instability of the parent compound. 
M. A. Hossain, B. Bohnenbuck, Y. D. Chuang, M. W. Haverkort, I. S.   Elfimov, A. Tanaka, A. G. Cruz, Z. Hu, H.-J. Lin, C. T....
cond-mat.str-el