EPR of Mn2+ in polycrystalline dolomite

Abstract

The EPR spectrum at 9.1 GHz of the M = l/2~-l/2 transition for Mn2+ in polycrystalline dolomite has been studied using a detailed computer simulation of the line shapes in the powder pattern spectrum. The accuracy of the analytical procedure was verified for the spectrum of Mn2+ in calcite, yielding magnetic constants which were in excellent agreement with previous polycrystalline and single crystal results. The EPR parameters obtained for Mn2+ in dolomite are g = 2.0020(2), A = -9.48(2) mT for Mn 2 + substituted in the Ca lattice site and g = 2.0028(2), A = -9.25(2) mT, D = 14.60(5) mT for substitution at the Mg site.

Determination of the hyperfine coupling constant and zero‐field splitting in the ESR spectrum of Mn2+ in calcite

“…1,10,15,20 -23,25,27,30 The values of D 0 range between 79.5 and 80.5 G with a mean value of 79.95 G, quite comparable with those present in literature. 1,10,20,21,25,27,30 …”

“…The position of the transitions depends on the linewidth and the lineshape. According to the previous simulations, 20,21,30 we consider a Lorentzian absorption function with a half-width  of 1 G.…”

“…Traditionally, the structure is described using the NaCl structure, with Na C replaced by Ca 2C and Cl by CO 3 29,30 Mn-O distances in the equatorial plane are ¾2.20Å and those in axial position are ¾2.26Å.…”

ESR Spectroscopy as a Tool for Identifying Joining Fragments of Antique Marbles: The Example of a Pulpit by Donatello and Michelozzo

“…In fact, using the values of the 13 C and 18 O isotope shifts, it has been possible to reassemble Greek stelae and identify incorrectly associated fragments (14). However, later work has shown that the variability of the isotope shifts within a marble block is usually a substantial fraction of the all-quarry variability, making fragments association extremely uncertain (15,16).…”

Room‐temperature ferromagnetism in Mn‐implanted TiO 2

“…4). The other structure is a double sextet (between 320 and 370 mT) arising from isolated Mn 2+ in TiO 2 [14]. a) b) This signal is not very much affected by the thermal annealing.…”