Brownleeite: A new manganese silicide mineral in an interplanetary dust particle

Abstract

Brownleeite, ideally stoichiometric MnSi, is a manganese silicide not previously observed in nature that was discovered within an interplanetary dust particle that likely originated from a comet. Three submicrometer brownleeite grains were found, with one of them poikilitically enclosed by Mnbearing forsterite. Owing to the small size of the brownleeite grains, it was not possible to determine conventional macroscopic properties of this mineral; however, the chemical composition and crystal structure were well constrained by extensive quantitative energy dispersive X-ray analysis and electron diffraction using transmission electron microscopy (TEM). The crystal system for brownleeite is cubic (a = 4.557 Å) with space group P2 1 3, cell volume = 94.63 Å 3 , Z = 4, density (calculated) = 2.913 g/cm 3 , and empirical formula: (Mn 0.77 Fe 0.18 Cr 0.05 )Si. These brownleeite grains likely formed as high-temperature condensates either in the early Solar System or in the outflow of an evolved star or supernova explosion.

Engineering helimagnetism in MnSi thin films

“…17 The bulk Curie temperature, T C , is 29.5 K. 16 For skyrmion-based spintronic applications, thin film materials are pivotal. 18 High-quality thin film MnSi has been grown by molecular beam epitaxy (MBE) on Si(111).…”

Presolar Grains From Novae: Evidence From Neon and Helium Isotopes in Comet Dust Collections

“…Some fragments of the same cluster particles from which the Suite 1 and 2 samples were extracted, and other clusters from the Grigg-Skellerup collection (GSC), are composed primarily of silicates, aluminum oxides, GEMS (glass with embedded metal and sulfides), and carbonaceous matter in various proportions (Nakamura-Messenger et al 2008). One of these contains the new mineral Brownleeite (Nakamura- Messenger et al 2010). However, given the chemical and mineralogic heterogeneity observed in different fragments from a single cluster IDP (Thomas et al 1995), the extent to which these compositional data are specifically applicable to the Suite 1 and 2 particles is uncertain.…”

Hydrothermal preparation of analogous matrix minerals of CM carbonaceous chondrites from metal alloy particles

“…The high-Si content of the MPPM shows similarity to the SiMn alloy found in IDPs (Nakamura-Messenger et al, 2008, 2010. The study of the compositions of the cores of terrestrial planets (e.g.…”

“…Earth and Mercury) has suggested that they probably contain substantial amounts of light elements, one of the most probable light elements may be metallic Si (Zambardi et al, 2013;Chabot et al, 2014), which show some similarity to the high-Si content of the MPPM. Theoretical calculations have proved that the existence of Al 63 Cu 24 Fe 13 , CuAl 2 , CuAl, AlCuFe, and SiMn alloys in the early solar system appears not to be contradictory to the canonical theory of solar nebula (the condensation theory; Nakamura-Messenger et al, 2010;Bindi et al, 2012). Thus, our above suggestions about the evolution of the parent asteroids of CM chondrites may be not completely groundless.…”