We have investigated ${\mathrm{NdCo}}_{2-x}{\mathrm{Ni}}_x$ cubic Laves compounds with 0 $\le x\le$ 1 using neutron diffraction and bulk magnetization measurements to study the influence of partial Ni substitutions of Co on the phase transitions and the magnetocaloric effect (MCE). Upon cooling, ${\mathrm{NdCo}}_2$ undergoes a cubic-to-tetragonal transition at 100 K and a tetragonal-to-orthorhombic transition at 42 K. The transitions are associated with long-range ferromagnetic ordering of the magnetic moments along the $c$ axis and spin reorientation into the $ab$ plane, respectively. Both transitions shift to lower temperatures as the Ni content $x$ increases. For $x\ge 0.5$, the orthorhombic phase is suppressed. Additionally, there was a reduction in the magnetic moment upon increasing the Ni substitution of Co. The MCE was determined both indirectly and directly, with good agreement between the methods. ${\mathrm{NdCo}}_2$ exhibits an adiabatic temperature change of 6.3 K for a field of 20 T, which is decreased to 4.9 K for NdCoNi for the same field strength due to the reduced magnetic moment upon Ni substitution.

Close

PrevNext

View figure in article

• First order phase transitions
• Magnetic phase transitions
• Magnetism
• Magnetocaloric effect
• Second order phase transitions
• Structural phase transition
• Neutron diffraction