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Autores principales: Pujari, Bhalchandra S., Gehlot, Sagar, Arjunwadkar, Mihir, Kanhere, Dilip G., Duraiswami, Raymond
Formato: Preprint
Publicado: 2023
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Acceso en línea:https://arxiv.org/abs/2308.06825
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author Pujari, Bhalchandra S.
Gehlot, Sagar
Arjunwadkar, Mihir
Kanhere, Dilip G.
Duraiswami, Raymond
author_facet Pujari, Bhalchandra S.
Gehlot, Sagar
Arjunwadkar, Mihir
Kanhere, Dilip G.
Duraiswami, Raymond
contents Cavansite is a visually stunning blue vanadosilicate mineral with limited occurrences worldwide, whereas Pentagonite is a closely related dimorph with similar physical and chemical properties, yet is extremely rare compared to Cavansite. The reasons behind Pentagonite's exceptional rarity remain largely unknown. In this study, (a) density functional theory (DFT) is utilized to investigate the electronic structures of Cavansite and Pentagonite at ground state and finite pressures; (b) a two-state Boltzmann probability model is then employed to construct a comprehensive phase diagram that reveals the abundance of each species across a wide range of pressure and temperature conditions; and (c) dehydration characteristics of these two minerals are explored. The present analysis reveals the key factors that contribute to the relative scarcity of Pentagonite, including differences in structural arrangement and electronic configurations between the two minerals. Specifically, it shows that (a) because of the peculiar arrangements of SiO4 polyhedra, Cavansite forms a compact structure (about 2.7% less in volume) resulting in lower energy; (b) at a temperature of about 650K only about 1% Pentagonite can form; (c) vanadium induces a highly localized state in both of these otherwise large-band-gap insulators resulting in an extremely weak magnetic phase that is unlikely to be observed at any reasonable finite temperature; and (d) water molecules are loosely bound inside the microporous crystals of Cavansite and Pentagonite, suggesting potential applications of these minerals in various technological fields.
format Preprint
id arxiv_https___arxiv_org_abs_2308_06825
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle On the relative abundances of Cavansite and Pentagonite
Pujari, Bhalchandra S.
Gehlot, Sagar
Arjunwadkar, Mihir
Kanhere, Dilip G.
Duraiswami, Raymond
Materials Science
Geophysics
Cavansite is a visually stunning blue vanadosilicate mineral with limited occurrences worldwide, whereas Pentagonite is a closely related dimorph with similar physical and chemical properties, yet is extremely rare compared to Cavansite. The reasons behind Pentagonite's exceptional rarity remain largely unknown. In this study, (a) density functional theory (DFT) is utilized to investigate the electronic structures of Cavansite and Pentagonite at ground state and finite pressures; (b) a two-state Boltzmann probability model is then employed to construct a comprehensive phase diagram that reveals the abundance of each species across a wide range of pressure and temperature conditions; and (c) dehydration characteristics of these two minerals are explored. The present analysis reveals the key factors that contribute to the relative scarcity of Pentagonite, including differences in structural arrangement and electronic configurations between the two minerals. Specifically, it shows that (a) because of the peculiar arrangements of SiO4 polyhedra, Cavansite forms a compact structure (about 2.7% less in volume) resulting in lower energy; (b) at a temperature of about 650K only about 1% Pentagonite can form; (c) vanadium induces a highly localized state in both of these otherwise large-band-gap insulators resulting in an extremely weak magnetic phase that is unlikely to be observed at any reasonable finite temperature; and (d) water molecules are loosely bound inside the microporous crystals of Cavansite and Pentagonite, suggesting potential applications of these minerals in various technological fields.
title On the relative abundances of Cavansite and Pentagonite
topic Materials Science
Geophysics
url https://arxiv.org/abs/2308.06825