Magnetic structure of TbNiAl4

Low temperature nuclear orientation observations of severe neutron activation damage in ( 160 Tb)TbNiAl 4

“…Applied magnetic fields of typically B ext = 0.5 T were aligned along the easy a axis for TbNiAl 4 , to provide a magnetising field for the thermometer. This is well below the first magnetic phase transition of TbNiAl 4 [6] and in keeping with the strong metamagnetic character of the compound there was no observable difference with the 160 Tb gamma anisotropy in zero applied field. LTNO gamma anisotropies were monitored by three HPGe detectors nominally aligned along each of the principal orthorhombic crystal axes.…”

“…In our paper a sample of extensive LTNO studies of the terminal compound, TbNiAl 4 , is presented with a view to understand the basic origins of the attenuated LTNO. This uniaxial, antiferromagnetic system was chosen because it is one of the best studied of the relevant compounds (known to undergo two magnetic phase transitions in both temperature and magnetic field manifolds [6]), and, most importantly, the Tb 3+ ion in TbNiAl 4 has a known saturated electronic moment state (8.6 μ B ) measured in very high magnetic fields [7].…”

Magnetocaloric effect in the ferromagnetic GdNi4M (M=Al, Si) and antiferromagnetic NdNiAl4 compounds

“…The NdNiAl 4 compound crystallizes in the YNiAl 4 -type orthorhombic structure and is antiferromagnetic [4][5][6] with the Nd moments ordered along the b-axis below T N = 9.5 K. A metamagnetic phase transition occurs for this compound at 4.4 T. The Ni atoms do not show a noticeable magnetism. For comparison, the isostructural PrNiAl 4 and TbNiAl 4 compounds reveal ordering along the a-axis [7,8], which results from the different magnetic anisotropies of the ions. The MCE properties studied within the present paper provides new observations about the phase transitions in the ferromagnetic RNi 4 M (R -rare earth) and the antiferromagnetic NdNiAl 4 compounds and it is shown that substitutions in the parent GdNi 5 binary compound can improve the MCE performance.…”

Low temperature nuclear orientation studies of the magnetic structures of RNiAl4 in applied magnetic fields

“…TbNiAl 4 is known to have 3 magnetic phases in the temperature manifold, in zero applied field. The intermediate phase is an incommensurate AF, while at low temperature it is a simple AF with the Tb 3+ moments pointing along the a axis [1]. The first of the two field induced transitions for TbNiAl 4 , can be seen in Fig.…”

“…TbNiAl 4 is one illustrative example. It has two phase transitions (three phases) as a function of temperature in low applied magnetic field, and also at least three phases as a function of applied magnetic field at low temperature [1]. Aligned with the first of these field driven transitions is a large inverse magneto-caloric effect (MCE) [2].…”