Vacancy-driven magnetocaloric effect in Prussian blue analogues

We experimentally show that the magnetocaloric properties of molecule-based Prussian blue analogues can be adjusted by controlling during the synthesis the amount of intrinsic vacancies. For Csx Ni4II [CrIII (CN)6](8 + x) / 3, we find indeed that the ferromagnetic phase transition induces significantly large magnetic entropy changes, whose maxima shift from ∼ 68 to ∼ 95 K by varying the number of [CrIII (CN)6]3 - vacancies, offering a unique tunability of the magnetocaloric effect in this complex. © 2007 Elsevier B.V. All rights reserved.