Paramagnetic two-dimensional silicon-oxide from natural silicates

Abstract

Silicon dioxide’s potential for having magnetic properties is fascinating, as combining its electronic capabilities with magnetic response seems promising for spintronics. In this work, the mechanisms that drive the change from diamagnetic behavior in pure silicates like SiO2 to paramagnetic behavior in transition metal-doped silicates like Rhodonite silicate (CaMn3Mn(Si5O15)) are explored. This naturally occurring Rhodonite (R)-silicate was thinned down while retaining its magnetic properties by liquid-phase scalable exfoliation. Exfoliating R-silicate into the two-dimensional (2D) structure by LPE increases magnetic coercivity, and the internal resistance to demagnetization (ΔHc) up to ∼23.95 Oe compared to 7.08 Oe for its bulk phase. DFT spin-polarized calculations corroborate those findings and explain that the origin of the magnetic moment comes mainly from the Mn in the doped 2D silicate due to the asymmetrical components of the Mn d and Si p states in the valence band. This result is further illustrated by the spin component differential charge densities showing that Mn and Si atoms display a residual up spin charge. Rhodonite’s unusual magnetic behavior has considerable potential for spintronics, data storage, and sensing technologies. Understanding the complex relationships between the structural, magnetic, and electronic properties of silicates is essential for developing new materials and composites as well as for driving future research.

A comprehensive review of atomically thin silicates and their applications

“…Sensitivity was about 0.2/ppm with major H 2 S gas adsorption at Mn sites of the material. Figure 7(f) again shows a study reported recently on the magnetic properties of 2D silicate (2D Rhodonite) compared to diamagnetic SiO 2 [95]. The study elaborately discusses, supported by DFT results, how the presence of transition metal atoms like Mn in the structure has a significant role in the transition from diamagnetic to paramagnetic character for pure SiO 2 and CaMn 3 MnSi 5 O 15 , respectively [95].…”

“…It is clear that 2D silicates present a wealth of opportunities for fundamental research as well as applications in science and cutting-edge technology. We hope the present work will stimulate [94,95] further investigations on this remarkable class of 2D materials.…”

“…Copyright (2023) American Chemical Society. (f) 2D Rhodonite magnetic property [95]. Reproduced from [95].…”

“…(f) 2D Rhodonite magnetic property [95]. Reproduced from [95]. © IOP Publishing Ltd. All rights reserved.…”

“…In the future, the high surface area, lightweight 2D silicates could be used in advanced electrical components for high-temperature environments, such as aerospace or automotive applications [109]. Moreover, the magnetic behavior of 2D natural silicates is paramagnetic [95], which can be utilized in building memory devices such as Resistance Switching Memory (RRAM) and Phase Change Memory (PCM). As per reports, organic field-effect transistors (OFETs) with mica electrets were used as multistate storage devices.…”