Ground-state degeneracy and complex magnetism of geometrically frustrated <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi mathvariant="normal">Gd</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">Ir</mml:mi><mml:mrow><mml:mn>0.97</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi mathvariant="normal">Si</mml:mi><mml:mrow><mml:mn>2.97</mml:mn></mml:mrow></mml:msub></mml:math>
Sudip Chakraborty, Shuvankar Gupta, Santanu Pakhira, R. N. P. Choudhary, Anis Biswas, Yaroslav Mudryk, V. K. Pecharsky, D. D. Johnson, Chandan Mazumdar
Abstract
A new triangular-lattice intermetallic compound ${\mathrm{Gd}}_{2}{\mathrm{Ir}}_{0.97}{\mathrm{Si}}_{2.97}$ was successfully synthesized as single phase by deliberately introducing vacancies. Theoretical analysis suggests that the ground state is competing with several low-energy spin configurations due to magnetic frustration on a nearly ideal triangular lattice. Despite a number of competing magnetic states, the compound exhibits long-range antiferromagnetic order at 16 K, a long-range ferrimagnetic transition at 6.5 K, and a reentrant cluster-glass transition below ${T}_{f}$ $\ensuremath{\sim}$ 3 K. The complex magnetism in the compound could be correlated with competing antiferromagnetic and ferrimagnetic structures predicted theoretically.