Controllable nonlinear optical properties of different-sized iron phosphorus trichalcogenide (FePS₃) nanosheets

Abstract

Two-dimensional iron phosphorus trichalcogenide (FePS3) has attracted significant attention for its use in electricity, magnetism and optical fields due to its outstanding physical and chemical properties. Herein, FePS3 was prepared using the chemical vapor transportation (CVT) method and then exfoliated by using fast electrochemical exfoliation. After gradient centrifugation, FePS3 nanosheets with thicknesses ranging from 1.5 to 20 nm and lateral dimensions of 0.5–3 μm were obtained. By utilizing the spatial self-phase modulation (SSPM) effect, the relationships between the nonlinear refractive index and the size of the FePS3 nanosheets were investigated in detail which revealed that the nonlinear refractive index can be effectively controlled by the size of the FePS3 nanosheets. It is worth noting that the optimal FePS3 nanosheets (3–5 layers thick and ∼1 μm in lateral dimensions) displayed the highest nonlinear refractive index of ∼10−5 cm2 W−1. This work demonstrates the potential that FePS3 nanosheets have for use in nonlinear optics or nonlinear optical devices.

Direct Magnetic Evidence, Functionalization, and Low-Temperature Magneto-Electron Transport in Liquid-Phase Exfoliated FePS3

“…This trend can be understood when inspecting the AFM statistical analysis performed in the four samples (see Figure and Figure S7 in the Supporting Information). Only a minor variation in the thickness distribution (<4 nm, 3–4 layers) can be observed between samples, in agreement with previous reports where thin flakes were obtained by chemical exfoliation . Therefore, only minor variations in T N could be expected.…”

“…The characteristic peaks of bulk FePS 3 appear below 600 cm –1 . , The most intense Raman band at 378 cm –1 (P 6 ) is assigned to the P–S symmetric stretching vibration. The 278 cm –1 (P 5 ), 245 cm –1 (P 4 ), and 219 cm –1 (P 3 ) peaks correspond to PS 3 deformations, ,, while the peak at 155 cm –1 (P 2 ) is assigned to the P–P single bond stretching . The low-frequency broad band around 93 cm –1 (P 1 ) involves vibrations of the transition-metal atom. ,,,,, The Raman spectra of the LPE flakes present the same characteristic modes at roughly the same energies.…”

“…The quality of the flakes additionally allows to study the electronic properties and perform large-scale covalent functionalization, as summarized in Figure a. We perform liquid-phase exfoliation (LPE) of FePS 3 in i PrOH. , We show that the exfoliation proceeds smoothly without the help of surfactant species or intercalating agents used in other liquid exfoliation methods. − Thousands of flakes, with a narrow and tunable thickness distribution, remain dispersed in i PrOH which can be easily quenched and measured in conventional SQUID magnetometers in solvent, avoiding reaggregation into solid-state . We obtain a direct evidence of the antiferromagnetic transition in thin flakes (5–9 layers) of FePS 3 .…”

Orbital and magnetic ordering in single-layer FePS3: A DFT+U study

“…What makes this material attractive compared to other 2D materials (especially transition-metal dichalcogenides and graphene) is its optical response over a broad range of the electromagnetic spectrum 8 . A band gap of about 1eV [8][9][10][11] makes FePS 3 suitable for infra-red detection while applications in ultraviolet photodetectors 12 and in non-linear optics 13 have been reported as well. In addition, pure bulk FePS 3 displays antiferromagnetic ordering below 120 K 6,14 while its magnetic and structural properties can be tuned easily 15 by chemical modification.…”

PVP‐Capped Gold Nanoparticles: Thermal Nonlinear Refraction Probed by Spatial Self‐Phase Modulation

“…[9] In addition to Au nanoparticles, the response by SSPM of Ag nanoparticles dispersed in different fluid carriers has also been analyzed. [10][11][12][13] SSPM has also been employed for studying the nonlinear optical properties of thermal origin of 2D nanostructured materials, for instance Bi 2 Se 3 -Bi 2 Te 3 heterostructures, [14] iron phosphorus trichalcogenides, [15] graphene oxide, [16] antimonene, [17] ultrathin niobium carbide sheets, [18] germanium selenide nanoflakes, [19] and fullerenes [20] and NbSe 2 [21] besides perovskite quantum dots [22] and silver nanocrystals of divers geometry. [23] Due to the high biocompatibility and optical properties, gold nanoparticles (AuNPs) of different shapes have been tested for numerous applications as theranostics, [24] biosensing and imaging, [25] cancer therapy, [26] and drug delivery.…”