Excellent Barocaloric\nEffect by Modulating Geometrical\nFrustrations in Mn<sub>3</sub>Pt

Barocaloric materials hold great promise for next-generation\nsolid-state\ncooling devices because of their green and efficient cooling performance.\nThe insights into low-pressure-driven barocaloric materials are expected\nto pave the way for the widespread application of barocaloric refrigeration\ntechnology. Here, we reveal the low-pressure-driven large barocaloric\neffect (BCE) modulated by geometrical frustrations in Mn<sub>3</sub>Pt. The highest sensitivity to pressure of Mn<sub>3</sub>Pt in metal\nBCE materials results in an excellent temperature-change strength\nof 9.77 K 100<sup>–1</sup> MPa<sup>–1</sup>. Neutron\npowder diffraction and first-principles calculations point out the\ndual effect of geometrical frustration on modulating the unusual BCE,\nwhich not only induces giant volume expansion by inspiring strong\nspin fluctuation and magnetic moment but also enhances the sensitivity\nof magnetic phase transition. The model of the dual effect of geometrical\nfrustration in magnets with geometrical frustration is established,\nwhich will promote the research progress of barocaloric refrigeration\ndevices.