Giant magnetocaloric effect in an exchange-frustrated GdCrTiO 5 antiferromagnet

摘要: We report the role of exchange frustration on magnetocaloric properties ${\mathrm{GdCrTiO}}_{5}$. Due to highly frustrated nature magnetic interactions, in ${\mathrm{GdCrTiO}}_{5}$, long-range antiferromagnetic ordering ${\mathrm{Gd}}^{3+}$ moments occurs at a much lower temperature ${T}_{N}=0.9$ K and cooling power enhances dramatically relative that observed several geometrically systems. Below 5 K, isothermal entropy change ($\ensuremath{-}\mathrm{\ensuremath{\Delta}}{S}_{\mathrm{m}}$) is found be 36 J ${\mathrm{kg}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$ for field ($\mathrm{\ensuremath{\Delta}}H$) 7 T. $\ensuremath{-}\mathrm{\ensuremath{\Delta}}{S}_{\mathrm{m}}$ shows saturationlike behavior with decreasing $T$ down 2 reversible nature. The adiabatic $\mathrm{\ensuremath{\Delta}}{T}_{\mathrm{ad}}$ 15.5 $\mathrm{\ensuremath{\Delta}}H=7$ These parameters are significantly larger than reported potential refrigerants, even small moderate changes. present result not only suggests ${\mathrm{GdCrTiO}}_{5}$ could considered as refrigerant cryogenic temperatures but also promotes further studies effect. In contrast, geometrical effect has been previously theoretically experimentally investigated very few