Lu14Co3In3-type Y14Co3Al3, Gd14Co3.2Al2.8, {Gd, Tb, Dy, Lu}14Ni3Al3 and {Tb, Dy}14Co3Al3 compounds: Crystal structure, magnetic properties and heat capacity

The crystal structure of new Lu14Co3In3-type {Gd, Tb, Lu}14Ni3Al3 compounds (P42/nmc. N 137, tP80) has been established using powder X-ray diffraction studies with cell parameters a = 0.95765(2) nm, c = 2.30214(5) nm for Gd14Ni3Al3, a = 0.95012(5) nm, c = 2.28190(10) nm for Tb14Ni3Al3 and a = 0.92604(2) nm, c = 2.23350(4) nm for Lu14Ni3Al3. Magnetic properties of the polycrystalline Y14Co3Al3, Gd14Co3.2Al2.8 and {Tb, Dy}14{Co, Ni}3Al3 have been studied by magnetization measurements. Y14Co3Al3 is paramagnetic down to 2 K, Gd14Co3.2Al2.8 exhibits ferro-antiferromagnetic ordering, while {Tb, Dy}14{Co, Ni}3Al3 show field sensitive pure antiferromagnetic ordering with field induced slight ferromagnetism. Heat capacity measurements (in zero applied magnetic field and field of 50 kOe) confirm metamagnetic-like transitions of Tb14Ni3Al3 and Dy14Ni3Al3.