Pulsed high-field NMR study on CeIn; High-field phase diagram near an antiferromagnetic QCP

Tokunaga, Yo  ; Orlova, A.*; Bruyant, N.*; Aoki, Dai*; Mayaffre, H.*; Krmer, S.*; Julien, M.-H.*; Berthier, C.*; Horvati, M.*; Sakai, Hironori   ; Hattori, Taisuke; Kambe, Shinsaku  ; Sheikin, I.*

In order to understand the origin of the field-induced anomaly observed in the heavy-fermion metal CeIn at about 45 T, well before the antiferromagnetic critical field, we have performed a pulsed magnetic field In-NMR study using a single crystal up to 56 Tesla. We confirmed that there is no obvious change of hyperfine fields at In sites even above 45 T. This indicates that there is no structural change at high fields, and further, denies simple explanations of the anomaly as due to a field-induced change of the magnetic structure in CeIn.