Abstrakt
We have studied development of structural and magnetic properties of TbNiAl single crystal under applied hydrostatic and uniaxial pressure. TbNiAl crystallizes in the hexagonal ZrNiAl-type structure.
The lattice parameters show a transition between two phases with different c/a ratio around 120 K as evidenced by X-ray diffraction, resistivity and thermal expansion measurements. The application of hydrostatic pressure stabilizes the low c/a phase.
The transition shifts consequently to lower temperatures with applied pressure and vanishes for pressure above 0.55 GPa. The magnetic properties are characterized by antiferromagnetic order below T-N = 45 K.
The application of magnetic field of 0.3 T along the c-axis leads to a metamagnetic transition to ferromagnetic order. The critical field of this transition shifts considerably to higher values with hydrostatic pressure whereas the uniaxial pressure applied along the c axis moves the transition to lower fields.
TbNiAl represents thus a rare example of a well localized system where the magnetic ground state is strongly influenced by external pressure. This behavior is discussed in connection with the structural parameters. (C) 2013 Elsevier B.V.
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