Strong Longitudinal Magnetic Fluctuations near Critical End Point in   UCoAl: A ^59Co-NMR Study
  We report ^59Co-NMR measurements in UCoAl where a metamagnetism occurs due to enhancement of ferromagnetism by magnetic field. The metamagnetic transition from a paramagnetic (PM) state to a ferromagnetic state is a first order transition at low temperatures, but it changes to a crossover at high temperatures on crossing the critical end pint (CEP) at T_CEP ~ 12 K. The contrasting behavior between the relaxation rates 1/T_1 and 1/T_2 suggests that the longitudinal magnetic fluctuation of U moment is strongly enhanced especially near the CEP. A wide diffusion of the fluctuation from the CEP can be confirmed even in the PM state where the magnetic transition does not occur. 
Hiroki Nohara, Hisashi Kotegawa, Hideki Tou, Tatsuma D. Matsuda,   Etsuji Yamamoto, Yoshinori Haga, Zachary Fisk, Yoshichika...
cond-mat.str-el