Magnetic neutron diffraction and pressure studies on CeRuSn

We have determined the influence of magnetic fields on the crystal and magnetic structures of CeRuSn using single crystal neutron diffraction and susceptibility measurements at various pressures up to 7.4 kbar and temperatures down to 1.6 K. CeRuSn adopts below 160 K an incommensurately modulated crystal structure. It orders antiferromagnetically below T_N=2.8 K in an incommensurate manner as well. This Néel-temperature is pressure independent up to 7.4 kbar. The neutron diffraction experiments detected a magnetic modulation vector q_mag = (0, 0, 0.175), however, it is commensurate with the incommensurate crystal structure with q_nuc = (0, 0, 0.35). At 0.6 T as well as at 0.9 T metamagnetic transitions have been observed via magnetic property measurements. The magnetic field of 0.9 T applied along the c-axis suppresses the magnetic reflections. The moments align ferromagnetically along the modulated crystal structure. Up to 3 T no change of the wavelength of the crystal structure modulations could be detected