The magnetic properties of a synthetic bornite, Cu5FeS4, and of a Mn-bearing synthetic bornite were investigated using Superconducting Quantum Interference Device (SQUID) magnetometry and room temperature X-band Electron Paramagnetic Resonance (EPR) spectroscopy. Samples were synthesised from the elements using conventional dry methods. Chemical and phase compositions of the samples were confirmed by means of Electron Probe Micro-Analysis (EPMA) and by powder X-Ray Diffraction (XRD). Experimental results, interpreted using spectral simulations, highlight the superexchange nature of ionic interactions between paramagnetic centres and the role played by partial intervalence charge transfer between the Fe(III) and Cu(I) species in natural and synthetic bornite. The cation distribution in synthetic samples was shown to be different from the natural sample, in spite of the close similarity in chemical composition and structure.
Magnetic properties and cation ordering in two synthetic bornite samples,Cu5(Fe, Mn)S4
DI BENEDETTO, FRANCESCO
;
2011
Abstract
The magnetic properties of a synthetic bornite, Cu5FeS4, and of a Mn-bearing synthetic bornite were investigated using Superconducting Quantum Interference Device (SQUID) magnetometry and room temperature X-band Electron Paramagnetic Resonance (EPR) spectroscopy. Samples were synthesised from the elements using conventional dry methods. Chemical and phase compositions of the samples were confirmed by means of Electron Probe Micro-Analysis (EPMA) and by powder X-Ray Diffraction (XRD). Experimental results, interpreted using spectral simulations, highlight the superexchange nature of ionic interactions between paramagnetic centres and the role played by partial intervalence charge transfer between the Fe(III) and Cu(I) species in natural and synthetic bornite. The cation distribution in synthetic samples was shown to be different from the natural sample, in spite of the close similarity in chemical composition and structure.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
