Magnetic-field dependence of antiferromagnetic structure in CeRh1−xCoxIn5

We investigated effects of magnetic field H on antiferromagnetic (AF) structures in CeRh1−xCoxIn5 by performing the elastic neutron scattering measurements. By applying H along the [11̄0] direction, the incommensurate AF state with the propagation vector of qh1 = (1/2, 1/2,0.297) observed at H = 0 is replaced by the commensurate AF state with the qc2 = (1/2, 1/2,1/4) modulation above 2 T for x = 0.23, while the AF states with the qc1 = (1/2,1/2, 1/2) and qh2 = (1/2,1/2,0.42) modulations seen at H = 0 change into a single qc1-AF state above ~ 1.6 T for x = 0.7. These results suggest the different types of AF correlation for Co concentrations of 0.23 and 0.7 in an applied magnetic field H.