title: Surface induces different crystal structures in a room temperature switchable spin crossover compound.
abstract: We investigated the influence of surfaces in the formation of different crystal structures of a spin crossover compound, namely [Fe(L)2] (LH: (2-(pyrazol-1-yl)-6-(1H-tetrazol-5-yl)pyridine), which is a neutral compound thermally switchable around room temperature. We observed that the surface induces the formation of two different crystal structures, which exhibit opposite spin transitions, i.e. on heating them up to the transition temperature, one polymorph switches from high spin to low spin and the second polymorph switches irreversibly from low spin to high spin. We attributed this inversion to the presence of water molecules H-bonded to the complex tetrazolyl moieties in the crystals. Thin deposits were investigated by means of polarized optical microscopy, atomic force microscopy, X-ray diffraction, X-ray absorption spectroscopy and micro Raman spectroscopy; moreover the analysis of the Raman spectra and the interpretation of spin inversion were supported by DFT calculations.
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN) Via P. Gobetti 101, 40129 Bologna, Italy. massimiliano.cavallini@cnr.it.
authors.forename: Denis
authors.initials: D
authors.lastname: Gentili
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi, (CNR-IMM) Via P. Gobetti 101, 40129 Bologna, Italy.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Liscio
authors.affiliation: Elettra - Sincrotrone Trieste, S.S. 14 Km 163.5 in Area Science Park, 34149 Basovizza - Trieste, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Demitri
authors.affiliation: Institute of Nanotechnology, Karlsruhe Institute of Technology, D-76344 Eggenstein-Leopoldshafen, Denmark.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schäfer
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN) Via P. Gobetti 101, 40129 Bologna, Italy. massimiliano.cavallini@cnr.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Borgatti
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (CNR-IOM), Laboratorio TASC, Area Science Park, I-34149 Trieste, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Torelli
authors.affiliation: Elettra - Sincrotrone Trieste, S.S. 14 Km 163.5 in Area Science Park, 34149 Basovizza - Trieste, Italy.
authors.forename: Benoit
authors.initials: B
authors.lastname: Gobaut
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (CNR-IOM), Laboratorio TASC, Area Science Park, I-34149 Trieste, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Panaccione
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (CNR-IOM), Laboratorio TASC, Area Science Park, I-34149 Trieste, Italy and Universita` di Milano, Dipartimento di Fisica, via Celoria 16, 20133 Milano, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Rossi
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività (CNR-ISOF) Via P. Gobetti 101, 40129 Bologna, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Degli Esposti
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività (CNR-ISOF) Via P. Gobetti 101, 40129 Bologna, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Gazzano
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi, (CNR-IMM) Via P. Gobetti 101, 40129 Bologna, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Milita
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN) Via P. Gobetti 101, 40129 Bologna, Italy. massimiliano.cavallini@cnr.it.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Bergenti
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN) Via P. Gobetti 101, 40129 Bologna, Italy. massimiliano.cavallini@cnr.it.
authors.forename: Giampiero
authors.initials: G
authors.lastname: Ruani
authors.affiliation: Institute of Inorganic Chemistry, Technology and Materials, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, 81237, Slovakia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Šalitroš
authors.affiliation: Institute of Nanotechnology, Karlsruhe Institute of Technology, D-76344 Eggenstein-Leopoldshafen, Denmark and Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg, 23, rue du Loess, BP 43, 67034, Strasbourg Cedex 2, France.
authors.forename: Mario
authors.initials: M
authors.lastname: Ruben
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN) Via P. Gobetti 101, 40129 Bologna, Italy. massimiliano.cavallini@cnr.it.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Cavallini