The effect of pressure on the band-gap energy in FePO4 and FeVO4

Sinhué López-Moreno; Josu Sánchez-Martín; Enrico Bandiello; Marco Bettinelli; Craig L. Bull; Christopher J. Ridley; Daniel Errandonea

doi:10.1016/j.jpcs.2023.111604

The effect of pressure on the band-gap energy in FePO₄ and FeVO₄

Sinhué López-Moreno
, Josu Sánchez-Martín
, Enrico Bandiello
, Marco Bettinelli
, Craig L. Bull
, Christopher J. Ridley
, Daniel Errandonea

Research output: Contribution to journal › Article › peer-review

7 Scopus citations

Abstract

In this work, we have studied the electronic structure of FePO₄ and FeVO₄ under high pressure by means of optical-absorption measurements and first-principles calculations. Samples of both compounds have been pressurized up to 6 GPa within a diamond-anvil cell to be characterized in the ultraviolet–visible-near infrared range. The optical-absorption measurements corroborated previously reported phase transitions: berlinite (P3₁21) ⟶ CrVO₄-type (Cmcm) in FePO₄, and FeVO₄-I (P1̄) ⟶ FeVO₄-I’ (P1̄) ⟶ FeVO₄-II’ (α-MnMoO₄-type, C2/m) in FeVO₄. According to our experiments, FePO₄ presents direct electronic band-gaps in both phases. In contrast, the low- and high-pressure phases of FeVO₄ have indirect band-gaps. In both compounds, the band-gap energy decreases with pressure. The computed electronic band structure revealed that the population at valence band maxima (VBM) and conduction band minima (CBM) changes with pressure in both FePO₄ and FeVO₄. Pressure-induced changes in Fe coordination modulate the occupation at VBM and CBM, being more pronounced the consequences in FePO₄ due to the shift from tetrahedral (FeO₄) to octahedral (FeO₆) coordination. We have also analyzed the charge density within the quantum theory of atoms in molecules (QTAIM) methodology to complement the electronic structure results by computing the Bader effective charges, the Laplacian, and ellipticity at the bond critical points for both compounds as a function of pressure.

Original language	English
Article number	111604
Journal	Journal of Physics and Chemistry of Solids
Volume	183
DOIs	https://doi.org/10.1016/j.jpcs.2023.111604
State	Published - Dec 2023
Externally published	Yes

Funding

S. L.-M. thanks CONACYT of Mexico for financial support through the program “Programa de Investigadoras e Investigadores por México”. D.E. thanks the financial support from the “Ministerio de Ciencia e Innovación” (DOI: 10.13039/501100011033) under Project PID2019-106383GB-C41 and PID2022-138076NB-C41 as well as through MALTA Consolider Team research network (RED2018-102612-T), and from Generalitat Valenciana, Spain under Grants PROMETEO CIPROM/2021/075-GREENMAT. This study forms part of the Advanced Materials program and is supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and by the Generalitat Valenciana, Spain under grant MFA/2022/007. J.S-M. acknowledges the Spanish Ministry of Science, Innovation, and Universities for the PRE2020-092198 predoctoral fellowship. E.B. acknowledges the Universitat Politècnica de València, Spain for his postdoctoral contract (program PAID-10-21). The authors gratefully acknowledge the computing time granted by LANCAD and CONACYT on the supercomputer Miztli at LSVP DGTIC UNAM. Also, the IPICYT Supercomputing National Center for Education & Research, grant TKII-R2023-SLM2. S. L.-M. thanks CONACYT of Mexico for financial support through the program “Programa de Investigadoras e Investigadores por México”. D.E. thanks the financial support from the “Ministerio de Ciencia e Innovación” (DOI: 10.13039/501100011033) under Project PID2019-106383GB-C41 and PID2022-138076NB-C41 as well as through MALTA Consolider Team research network (RED2018-102612-T), and from Generalitat Valenciana, Spain under Grants PROMETEO CIPROM/2021/075-GREENMAT . This study forms part of the Advanced Materials program and is supported by MCIN with funding from European Union NextGenerationEU ( PRTR-C17.I1 ) and by the Generalitat Valenciana, Spain under grant MFA/2022/007 . J.S-M. acknowledges the Spanish Ministry of Science, Innovation, and Universities for the PRE2020-092198 predoctoral fellowship. E.B. acknowledges the Universitat Politècnica de València, Spain for his postdoctoral contract (program PAID-10-21 ). The authors gratefully acknowledge the computing time granted by LANCAD and CONACYT on the supercomputer Miztli at LSVP DGTIC UNAM. Also, the IPICYT Supercomputing National Center for Education & Research , grant TKII-R2023-SLM2 .

Keywords

Absorption measurements
Electronic properties
First-principles calculations
Phosphate fePO
Vanadate feVO

Access to Document

10.1016/j.jpcs.2023.111604

Cite this

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title = "The effect of pressure on the band-gap energy in FePO4 and FeVO4",

abstract = "In this work, we have studied the electronic structure of FePO4 and FeVO4 under high pressure by means of optical-absorption measurements and first-principles calculations. Samples of both compounds have been pressurized up to 6 GPa within a diamond-anvil cell to be characterized in the ultraviolet–visible-near infrared range. The optical-absorption measurements corroborated previously reported phase transitions: berlinite (P3121) ⟶ CrVO4-type (Cmcm) in FePO4, and FeVO4-I (P{\=1}) ⟶ FeVO4-I{\textquoteright} (P{\=1}) ⟶ FeVO4-II{\textquoteright} (α-MnMoO4-type, C2/m) in FeVO4. According to our experiments, FePO4 presents direct electronic band-gaps in both phases. In contrast, the low- and high-pressure phases of FeVO4 have indirect band-gaps. In both compounds, the band-gap energy decreases with pressure. The computed electronic band structure revealed that the population at valence band maxima (VBM) and conduction band minima (CBM) changes with pressure in both FePO4 and FeVO4. Pressure-induced changes in Fe coordination modulate the occupation at VBM and CBM, being more pronounced the consequences in FePO4 due to the shift from tetrahedral (FeO4) to octahedral (FeO6) coordination. We have also analyzed the charge density within the quantum theory of atoms in molecules (QTAIM) methodology to complement the electronic structure results by computing the Bader effective charges, the Laplacian, and ellipticity at the bond critical points for both compounds as a function of pressure.",

keywords = "Absorption measurements, Electronic properties, First-principles calculations, Phosphate fePO, Vanadate feVO",

author = "Sinhu{\'e} L{\'o}pez-Moreno and Josu S{\'a}nchez-Mart{\'i}n and Enrico Bandiello and Marco Bettinelli and Bull, \{Craig L.\} and Ridley, \{Christopher J.\} and Daniel Errandonea",

note = "Publisher Copyright: {\textcopyright} 2023 Elsevier Ltd",

year = "2023",

month = dec,

doi = "10.1016/j.jpcs.2023.111604",

language = "English",

volume = "183",

journal = "Journal of Physics and Chemistry of Solids",

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T1 - The effect of pressure on the band-gap energy in FePO4 and FeVO4

AU - López-Moreno, Sinhué

AU - Sánchez-Martín, Josu

AU - Bandiello, Enrico

AU - Bettinelli, Marco

AU - Bull, Craig L.

AU - Ridley, Christopher J.

AU - Errandonea, Daniel

PY - 2023/12

Y1 - 2023/12

N2 - In this work, we have studied the electronic structure of FePO4 and FeVO4 under high pressure by means of optical-absorption measurements and first-principles calculations. Samples of both compounds have been pressurized up to 6 GPa within a diamond-anvil cell to be characterized in the ultraviolet–visible-near infrared range. The optical-absorption measurements corroborated previously reported phase transitions: berlinite (P3121) ⟶ CrVO4-type (Cmcm) in FePO4, and FeVO4-I (P1̄) ⟶ FeVO4-I’ (P1̄) ⟶ FeVO4-II’ (α-MnMoO4-type, C2/m) in FeVO4. According to our experiments, FePO4 presents direct electronic band-gaps in both phases. In contrast, the low- and high-pressure phases of FeVO4 have indirect band-gaps. In both compounds, the band-gap energy decreases with pressure. The computed electronic band structure revealed that the population at valence band maxima (VBM) and conduction band minima (CBM) changes with pressure in both FePO4 and FeVO4. Pressure-induced changes in Fe coordination modulate the occupation at VBM and CBM, being more pronounced the consequences in FePO4 due to the shift from tetrahedral (FeO4) to octahedral (FeO6) coordination. We have also analyzed the charge density within the quantum theory of atoms in molecules (QTAIM) methodology to complement the electronic structure results by computing the Bader effective charges, the Laplacian, and ellipticity at the bond critical points for both compounds as a function of pressure.

AB - In this work, we have studied the electronic structure of FePO4 and FeVO4 under high pressure by means of optical-absorption measurements and first-principles calculations. Samples of both compounds have been pressurized up to 6 GPa within a diamond-anvil cell to be characterized in the ultraviolet–visible-near infrared range. The optical-absorption measurements corroborated previously reported phase transitions: berlinite (P3121) ⟶ CrVO4-type (Cmcm) in FePO4, and FeVO4-I (P1̄) ⟶ FeVO4-I’ (P1̄) ⟶ FeVO4-II’ (α-MnMoO4-type, C2/m) in FeVO4. According to our experiments, FePO4 presents direct electronic band-gaps in both phases. In contrast, the low- and high-pressure phases of FeVO4 have indirect band-gaps. In both compounds, the band-gap energy decreases with pressure. The computed electronic band structure revealed that the population at valence band maxima (VBM) and conduction band minima (CBM) changes with pressure in both FePO4 and FeVO4. Pressure-induced changes in Fe coordination modulate the occupation at VBM and CBM, being more pronounced the consequences in FePO4 due to the shift from tetrahedral (FeO4) to octahedral (FeO6) coordination. We have also analyzed the charge density within the quantum theory of atoms in molecules (QTAIM) methodology to complement the electronic structure results by computing the Bader effective charges, the Laplacian, and ellipticity at the bond critical points for both compounds as a function of pressure.

KW - Absorption measurements

KW - Electronic properties

KW - First-principles calculations

KW - Phosphate fePO

KW - Vanadate feVO

UR - https://www.scopus.com/pages/publications/85169052511

U2 - 10.1016/j.jpcs.2023.111604

DO - 10.1016/j.jpcs.2023.111604

M3 - Article

AN - SCOPUS:85169052511

SN - 0022-3697

VL - 183

JO - Journal of Physics and Chemistry of Solids

JF - Journal of Physics and Chemistry of Solids

M1 - 111604

ER -