Large adiabatic temperature change and magnetic frustration in triangular lattice antiferromagnet Dy2IrSi3

While previous studies reveal that the formation of polycrystalline R2TX3 (R = rare-earth, T = transition metal, X =p -block element) type compounds with T = Ir and Co is not achievable without deliberate introduction of atomic vacancies of Ir/Co and Si, we report successful synthesis of Dy2IrSi3 with fully stoichiometric ratio of constituent elements. An antiferromagnetic transition is manifested in the compound at 6.6 K where only about 50 % of Dy spins take part, while the rest remain in highly frustrated state due to edge -sharing triangular lattice geometry. The magnetic frustration is conclusively probed through magnetization, heat capacity and magnetocaloric study and the frustration parameter (f = divide theta p divide /TN, theta p, TN being Curie -Weiss and Ne ' el temperatures, respectively) in this case is as large as - 3. An additional cluster -glass type transition at -2.8 K observed in this system has likely been originated due to this magnetic frustration. The magnetocaloric effect reveals an adiabatic temperature change of -7.5 K for 70 kOe magnetic field, which is one of the largest values reported in intermetallic compounds.