Relaxation and magnetocaloric effect in the Mn12 molecular nanomagnet incorporated into mesoporous silica: a comparative study. Issue 54 (18th May 2016)

• Record Type: Journal Article
• Authors: Bałanda, Maria; Pełka, Robert; Fitta, Magdalena; Laskowski, Łukasz; Laskowska, Magdalena
• Is Part Of: RSC advances. Volume 6:Issue 54(2016)
• Page Start: 49179
• Page End: 49186
• Publication Date: 2016-05-18
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra04063b
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Successful incorporation of the Mn12 molecules into silica channels has been attested with AC susceptometry and magnetocaloric effect measurements. Abstract : This paper presents the synthesis and investigation of the magnetic properties of mesoporous silica SBA-15 functionalized with Mn12 ([Mn12 O12 (CH3 COO)16 (H2 O)4 ]·2CH3 COOH·4H2 O) high-spin molecular clusters. The SBA-Mn12 sample has been examined by means of X-ray diffraction, infrared spectroscopy, nitrogen sorption and TEM techniques. AC and DC magnetic measurements, including measurements of the magnetocaloric effect (MCE) were carried out both for SBA-Mn12 and for polycrystalline Mn12 . An increase in the activation energy and in the distribution of relaxation times was observed for SBA-Mn12 as compared to those of Mn12 . Differences in the MCE were also revealed. The maximum magnetic entropy change at the field change of 50 kOe for SBA-Mn12 is equal to 13.8 J K −1 mol −1 at T = 2.8 K, which is significantly less than 25.3 J K −1 mol −1 observed for Mn12 at 3.2 K. The altered relaxation and the magnetocaloric effect point to a successful incorporation of Mn12 molecules into the silica channels.