Magnetic behavior of trioctahedral micas with different octahedral Fe ordering |
| |
Authors: | Stefano Pini Maria Franca Brigatti Marco Affronte Daniele Malferrari Augusto Marcelli |
| |
Affiliation: | 1. Dipartimento di Scienze della Terra, Università di Modena e Reggio Emilia, Via S. Eufemia, 19, 41100, Modena, Italy 2. Dipartimento di Fisica, Università di Modena e Reggio Emilia, Via G. Campi 213/a, 41100, Modena, Italy 3. INFN-LNF, Via E. Fermi 40, 00044, Frascati, RM, Italy
|
| |
Abstract: | This contribution is finalized at the discussion of the magnetic structure of two samples, belonging to phlogopite–annite [sample TK, chemical composition IV(Si2.76Al1.24) VI(Al0.64Mg0.72 $ {text{Fe}}_{1.45}^{2 + } $ Mn0.03Ti0.15) (K0.96Na0.05) O10.67 (OH)1.31 Cl0.02] and polylithionite–siderophyllite joints [sample PPB, chemical composition IV(Si3.14Al0.86)VI(Al0.75Mg0.01 $ {text{Fe}}_{1.03}^{2 + } $ $ {text{Fe}}_{1.03}^{3 + } $ Mn0.01Ti0.01Li1.09) (K0.99Na0.01) O10.00 (OH)0.65F1.35]. Samples differ for Fe ordering in octahedral sites, Fe2+/(Fe2+?+?Fe3+) ratio, octahedral composition, defining a different environment around Fe cations, and layer symmetry. Spin-glass behavior was detected for both samples, as evidenced by the dependency of the temperature giving the peak in the susceptibility curve from the frequency of the applied alternating current magnetic field. The crystal chemical features are associated to the different temperature at which the maximum in magnetic susceptibility is observed: 6?K in TK, where Fe is disordered in all octahedral sites, and 8?K in PPB sample, showing a smaller and more regular coordination polyhedron for Fe, which is ordered in the trans-site and in one of the two cis-sites. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|