We performed nuclear-magnetic-resonance measurements on itinerant-electron metamagnet UCoAl to investigate the critical behavior of the magnetism near a metamagnetic (MM) critical endpoint (CEP). We derived c-axis magnetization M c and its fluctuation S c from the measurements of Knight shift and nuclear spin-lattice relaxation rate 1/T 1 as a function of the c-axis external field (H c) and temperature (T). We developed contour plots of M c and S c on the H c-T phase diagram, and observed the strong divergence of S c at the CEP. The critical exponents of M c and S c near the CEP are estimated and found to be close to the universal properties of a three-dimensional Ising model. We indicate that the critical phenomena at the itinerant-electron MM CEP in UCoAl have a common feature as a gas-liquid transition.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2012 Jul 23|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics