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arXiv · 2007.15453

Structure and magnetism of a new hexagonal polymorph of Ba$_3$Tb(BO$_3$)$_3$ with a quasi-2D triangular lattice

Nicola Kelly·Cheng Liu·Siân Dutton
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Abstract

This article reports the structural and magnetic characterisation of a new hexagonal ($P6_3cm$) low-temperature phase of Ba$_3$Tb(BO$_3$)$_3$, isostructural with the heavier lanthanide borates with formula Ba$_3$Ln(BO$_3$)$_3$ (Ln = Dy-Lu). The crystal structure contains a quasi-two-dimensional (2D) triangular lattice of Tb$^{3+}$ ions and is predicted to display unusual magnetic behaviour as a result of the low dimensionality. Magnetic susceptibility $\chi(T)$ shows antiferromagnetic interactions ($\theta_{CW} = -7.15$ K) and no sharp ordering transition at $T \geq 2$ K, but analysis of $\chi'(T)$, isothermal magnetisation and heat capacity suggests the possibility of short-range ordering at $T \approx 10$ K. The material exhibits an inverse magnetocaloric effect at $T < 4$ K.

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Nicola Kelly, Cheng Liu, Siân Dutton. 2020-07-30. Structure and magnetism of a new hexagonal polymorph of Ba$_3$Tb(BO$_3$)$_3$ with a quasi-2D triangular lattice. https://doi.org/10.1016/j.jssc.2020.121640

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