NMR determination of an incommensurate helical antiferromagnetic structure in EuCo2As2

作者：Ding Q P^*; Higa N; Sangeetha N S; Johnston D C; Furukawa Y

来源：PHYSICAL REVIEW B, 2017, 95(18): 184404.

DOI：10.1103/PhysRevB.95.184404

We report Eu-153, As-75, and Co-59 nuclear magnetic resonance (NMR) results on EuCo2As2 single crystal. Observations of Eu-153 and As-75 NMR spectra in zero magnetic field at 4.3 K below an antiferromagnetic (AFM) ordering temperature T-N = 45 K and its external magnetic field dependence clearly evidence an incommensurate helical AFM structure in EuCo2As2. Furthermore, based on Co-59 NMR data in both the paramagnetic and the incommensurate AFM states, we have determined the model-independent value of the AFM propagation vector k = (0,0,0.73 +/- 0.07)2 pi/c, where c is the c lattice parameter. Thus the incommensurate helical AFM state was characterized by only NMR data with model-independent analyses, showing NMR to be a unique tool for determination of the spin structure in incommensurate helical AFMs.

• 出版日期2017-5-5