title: Self-Enhancement of Rotating Magnetocaloric Effect in Anisotropic Two-Dimensional (2D) Cyanido-Bridged MnII-NbIVMolecular Ferrimagnet.
abstract: The rotating magnetocaloric effect (RMCE) is a new issue in the field of magnetic refrigeration. We have explored this subject on the two-dimensional (2D) enantiopure {[MnII(R-mpm)2]2[NbIV(CN)8]}·4H2O (where mpm = α-methyl-2-pyridinemethanol) coordination ferrimagnet. In this study, the magnetic and magnetocaloric properties of single crystals were investigated along the bc//H easy plane and the a*//H hard axis. The observed small easy plane anisotropy is due to the dipole-dipole interactions. For fields higher than 0.5 T, no significant difference in the magnetocaloric effect between both geometries was noticed. The maximal magnetic entropy change for conventional effect was observed at 32 K and the magnetic field change μ0ΔH = 5.0 T attaining the value of ∼5 J mol-1K-1. The obtained maximal value of -ΔSmis comparable to previously reported results for polycrystalline octacyanidoniobate-based bimetallic coordination polymers. A substantial anisotropy of magnetocaloric effect between the easy plane and hard axis appears in low fields. This includes the presence of inverse magnetocaloric effect only for the a*//H direction. The difference between both geometries was used to study the rotating magnetocaloric effect. We show that the inverse part of magnetocaloric effect can be used to enhance the rotating magnetic entropy change up to 51%. This finding is of key importance for searching efficient materials for RMCE.
authors.affiliation: Institute of Nuclear Physics PAN , Radzikowskiego 152, 31-342 Kraków, Poland.
authors.forename: Piotr
authors.identifier: http://orcid.org/0000-0002-0024-9557
authors.initials: P
authors.lastname: Konieczny
authors.affiliation: Institute of Nuclear Physics PAN , Radzikowskiego 152, 31-342 Kraków, Poland.|Faculty of Physics and Applied Computer Science, AGH University of Science and Technology , al. Mickiewicza 30, 30-059 Kraków, Poland.
authors.forename: Łukasz
authors.identifier: http://orcid.org/0000-0002-4050-7506
authors.initials: Ł
authors.lastname: Michalski
authors.affiliation: Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Podgajny
authors.affiliation: Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Szymon
authors.initials: S
authors.lastname: Chorazy
authors.affiliation: Institute of Nuclear Physics PAN , Radzikowskiego 152, 31-342 Kraków, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Pełka
authors.affiliation: Institute of Nuclear Physics PAN , Radzikowskiego 152, 31-342 Kraków, Poland.|Faculty of Physics and Applied Computer Science, AGH University of Science and Technology , al. Mickiewicza 30, 30-059 Kraków, Poland.
authors.forename: Dominik
authors.identifier: http://orcid.org/0000-0003-3201-3765
authors.initials: D
authors.lastname: Czernia
authors.affiliation: Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Szymon
authors.initials: S
authors.lastname: Buda
authors.affiliation: Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Mlynarski
authors.affiliation: Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Sieklucka
authors.affiliation: Institute of Nuclear Physics PAN , Radzikowskiego 152, 31-342 Kraków, Poland.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Wasiutyński