Magnetic phase transition and magnetic properties in rare-earth-based RAl3C3 layered carbides

High-purity RAl3C3 phases (R = Nd, Gd, Tb, Dy, Ho, Er and Tm) have been synthesized and all crystallized in hexagonal structure with the space group (#194) P63/mmc. Lattice parameters are decreased from R = Nd to R = Tm due to lanthanide contraction. Two nonlinear antiferromagnetic states are found in NdAl3C3 phase. While simple ferromagnetic state is observed for R = Gd, Tb, Ho and Er cases. A high coercivity of 0.45 T has been achieved in TbAl3C3 phase at 4 K indicating the uniaxial magnetocrystalline anisotropy. Before entering into paramagnetic state, DyAl3C3 phase undergoes the complex magnetic phase transition with increasing temperature. All these phase transitions are of second-order due to nonhysteresis.