X-ray photoelectron spectroscopy (XPS) and magnetic susceptibility studies of copper-vanadium phosphate glasses

G. D. Khattak; M. A. Salim; L. E. Wenger; A. H. Gilani

doi:10.1016/S0022-3093(99)00700-0

X-ray photoelectron spectroscopy (XPS) and magnetic susceptibility studies of copper-vanadium phosphate glasses

G. D. Khattak^*
, M. A. Salim
, L. E. Wenger
, A. H. Gilani

^*Corresponding author for this work

King Fahd University of Petroleum & Minerals

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

64 Scopus citations

Abstract

Vanadium phosphate glasses containing CuO with the chemical composition [(V₂O₅)_0.6-x(P₂O₅)_0.4(CuO) _x], where x = 0.0, 0.1, 0.2 and 0.3, have been prepared and investigated by X-ray photoelectron spectroscopy (XPS) and magnetization measurements. The core-level binding energies of O 1s, P 2p, P 2s, Cu 2p and V 2p have been measured with the P 2p and P 2s peaks shifting by about 2 eV towards lower binding energies in the CuO-vanadium phosphate glasses from their values in P₂O₅, while the V 2p peaks shift by approximately 0.3 eV towards lower binding energies from V₂O₅ and the Cu 2p peaks shift by approximately 0.8 eV towards higher binding energies from CuO. These shifts can be accounted for by changes in the next-nearest neighbor environment around the P, Cu and V atoms and the reduction in the valence state of the Cu and V ions. The O 1s spectrum is fitted to two peaks and the variation in the ratio of the peak areas is discussed in terms of the local structure as well. In addition, the Cu 2p_3/2 and Cu 2p_1/2 peak show doublet structures in the XPS spectra which are associated with the presence of both Cu⁺ and Cu²⁺ in these glasses; although the XPS results indicate that more than 90% of the Cu ions exist in the Cu²⁺ state. Likewise a multivalent state for the V ions is indicated by an asymmetry and broadening in the V 2p spectra as the CuO concentration in the glasses increases. This tendency is also observed in the magnetic susceptibility results as the ratios V⁵⁺/V_total determined from XPS are in qualitative agreement with those determined by using the susceptibility measurements combined with inductively coupled plasma (ICP) spectroscopy results. Furthermore the susceptibility data appear to follow a Curie-Weiss behavior (χ = C/(T-θ)) for temperatures above approximately 40 K with negative Curie temperatures indicating that the predominate magnetic interactions between the Cu²⁺-Cu²⁺ and Cu²⁺-V⁴⁺ exchange pairs are antiferromagnetic in nature.

Original language	English
Pages (from-to)	66-79
Number of pages	14
Journal	Journal of Non-Crystalline Solids
Volume	262
Issue number	1
DOIs	https://doi.org/10.1016/S0022-3093(99)00700-0
State	Published - Feb 2000

Bibliographical note

Funding Information:
The support of the KFUPM Physics Department and Research Committee (Grant PH/PHYSPROP/43) and the WSU Institute for Manufacturing Research is greatly acknowledged. The assistance of Mr M.A. Khan for experimental work is appreciated. Appendix A To determine the V 4+ /V total ratio from magnetic susceptibility and ICP data, we will define V 4+ / V total ratio of number of V 4+ ions to total number of V ions V 5+ / V total ratio of number of V 5+ ions to total number of V ions (1− V 4+ / V total ) N V number of vanadium ions/gram of sample from ICP N Cu number of copper ions/gram of sample from ICP C expt Curie constant (emu . K/Oe . gram) from χ -vs- T results. Assuming Cu only exists in Cu 2+ state ( p eff =1.9 μ B ) and V is in either the V 5+ (p eff =0) or V 4+ ( p eff =1.8 μ B ) states, the Curie constant is given by (A.1) C expt =N Cu [p eff ( Cu 2+ )] 2 3k B + V 4+ V total N V [p eff ( V 4+ )] 2 3k B . Thus the V 4+ /V total ratio can be determined from Eq. (1) by using the experimental determined values for C expt , N V and N Cu . Using the resulting value of the V 4+ /V total ratio, the molar fraction of V 2 O 5 , V 2 O 4 , P 2 O 5 and CuO as well as the molecular weight MW s of the glass sample can be determined. Recall that one mole of these CuO–vanadium phosphate glasses will have Avogadro number, N A , of molecules (A.2) N A = 1 2 V 4+ V total N V MW V 2 O 4 + 1 2 N V 1− V 4+ V total MW V 2 O 5 +N Cu MW CuO + 1 2 N P MW P 2 O 5 , where N P is the number of P ions per gram and is determined from Eq. (A.2) . Then (A.3) MW s =N A 1 2 V 4+ V total N V + 1 2 N V 1− V 4+ V total +N Cu + 1 2 N P , and the molar fraction of each constituent will be N V 2 O 4 = 1 2 V 4+ V total N V MW S N A N V 2 O 5 = 1 2 1− V 4+ V total N V MW S N A N CuO =N Cu MW S N A N P 2 O 5 = 1 2 N P MW S N A .

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Ceramics and Composites
Condensed Matter Physics
Materials Chemistry

Access to Document

10.1016/S0022-3093(99)00700-0

Cite this

@article{6a410e058b114988859c3a66b528780d,

title = "X-ray photoelectron spectroscopy (XPS) and magnetic susceptibility studies of copper-vanadium phosphate glasses",

abstract = "Vanadium phosphate glasses containing CuO with the chemical composition [(V2O5)0.6-x(P2O5)0.4(CuO) x], where x = 0.0, 0.1, 0.2 and 0.3, have been prepared and investigated by X-ray photoelectron spectroscopy (XPS) and magnetization measurements. The core-level binding energies of O 1s, P 2p, P 2s, Cu 2p and V 2p have been measured with the P 2p and P 2s peaks shifting by about 2 eV towards lower binding energies in the CuO-vanadium phosphate glasses from their values in P2O5, while the V 2p peaks shift by approximately 0.3 eV towards lower binding energies from V2O5 and the Cu 2p peaks shift by approximately 0.8 eV towards higher binding energies from CuO. These shifts can be accounted for by changes in the next-nearest neighbor environment around the P, Cu and V atoms and the reduction in the valence state of the Cu and V ions. The O 1s spectrum is fitted to two peaks and the variation in the ratio of the peak areas is discussed in terms of the local structure as well. In addition, the Cu 2p3/2 and Cu 2p1/2 peak show doublet structures in the XPS spectra which are associated with the presence of both Cu+ and Cu2+ in these glasses; although the XPS results indicate that more than 90\% of the Cu ions exist in the Cu2+ state. Likewise a multivalent state for the V ions is indicated by an asymmetry and broadening in the V 2p spectra as the CuO concentration in the glasses increases. This tendency is also observed in the magnetic susceptibility results as the ratios V5+/Vtotal determined from XPS are in qualitative agreement with those determined by using the susceptibility measurements combined with inductively coupled plasma (ICP) spectroscopy results. Furthermore the susceptibility data appear to follow a Curie-Weiss behavior (χ = C/(T-θ)) for temperatures above approximately 40 K with negative Curie temperatures indicating that the predominate magnetic interactions between the Cu2+-Cu2+ and Cu2+-V4+ exchange pairs are antiferromagnetic in nature.",

author = "Khattak, \{G. D.\} and Salim, \{M. A.\} and Wenger, \{L. E.\} and Gilani, \{A. H.\}",

note = "Funding Information: The support of the KFUPM Physics Department and Research Committee (Grant PH/PHYSPROP/43) and the WSU Institute for Manufacturing Research is greatly acknowledged. The assistance of Mr M.A. Khan for experimental work is appreciated. Appendix A To determine the V 4+ /V total ratio from magnetic susceptibility and ICP data, we will define V 4+ / V total ratio of number of V 4+ ions to total number of V ions V 5+ / V total ratio of number of V 5+ ions to total number of V ions (1− V 4+ / V total ) N V number of vanadium ions/gram of sample from ICP N Cu number of copper ions/gram of sample from ICP C expt Curie constant (emu . K/Oe . gram) from χ -vs- T results. Assuming Cu only exists in Cu 2+ state ( p eff =1.9 μ B ) and V is in either the V 5+ (p eff =0) or V 4+ ( p eff =1.8 μ B ) states, the Curie constant is given by (A.1) C expt =N Cu [p eff ( Cu 2+ )] 2 3k B + V 4+ V total N V [p eff ( V 4+ )] 2 3k B . Thus the V 4+ /V total ratio can be determined from Eq. (1) by using the experimental determined values for C expt , N V and N Cu . Using the resulting value of the V 4+ /V total ratio, the molar fraction of V 2 O 5 , V 2 O 4 , P 2 O 5 and CuO as well as the molecular weight MW s of the glass sample can be determined. Recall that one mole of these CuO–vanadium phosphate glasses will have Avogadro number, N A , of molecules (A.2) N A = 1 2 V 4+ V total N V MW V 2 O 4 + 1 2 N V 1− V 4+ V total MW V 2 O 5 +N Cu MW CuO + 1 2 N P MW P 2 O 5 , where N P is the number of P ions per gram and is determined from Eq. (A.2) . Then (A.3) MW s =N A 1 2 V 4+ V total N V + 1 2 N V 1− V 4+ V total +N Cu + 1 2 N P , and the molar fraction of each constituent will be N V 2 O 4 = 1 2 V 4+ V total N V MW S N A N V 2 O 5 = 1 2 1− V 4+ V total N V MW S N A N CuO =N Cu MW S N A N P 2 O 5 = 1 2 N P MW S N A . ",

year = "2000",

month = feb,

doi = "10.1016/S0022-3093(99)00700-0",

language = "English",

volume = "262",

pages = "66--79",

journal = "Journal of Non-Crystalline Solids",

issn = "0022-3093",

publisher = "Elsevier B.V.",

number = "1",

}

TY - JOUR

T1 - X-ray photoelectron spectroscopy (XPS) and magnetic susceptibility studies of copper-vanadium phosphate glasses

AU - Khattak, G. D.

AU - Salim, M. A.

AU - Wenger, L. E.

AU - Gilani, A. H.

N1 - Funding Information: The support of the KFUPM Physics Department and Research Committee (Grant PH/PHYSPROP/43) and the WSU Institute for Manufacturing Research is greatly acknowledged. The assistance of Mr M.A. Khan for experimental work is appreciated. Appendix A To determine the V 4+ /V total ratio from magnetic susceptibility and ICP data, we will define V 4+ / V total ratio of number of V 4+ ions to total number of V ions V 5+ / V total ratio of number of V 5+ ions to total number of V ions (1− V 4+ / V total ) N V number of vanadium ions/gram of sample from ICP N Cu number of copper ions/gram of sample from ICP C expt Curie constant (emu . K/Oe . gram) from χ -vs- T results. Assuming Cu only exists in Cu 2+ state ( p eff =1.9 μ B ) and V is in either the V 5+ (p eff =0) or V 4+ ( p eff =1.8 μ B ) states, the Curie constant is given by (A.1) C expt =N Cu [p eff ( Cu 2+ )] 2 3k B + V 4+ V total N V [p eff ( V 4+ )] 2 3k B . Thus the V 4+ /V total ratio can be determined from Eq. (1) by using the experimental determined values for C expt , N V and N Cu . Using the resulting value of the V 4+ /V total ratio, the molar fraction of V 2 O 5 , V 2 O 4 , P 2 O 5 and CuO as well as the molecular weight MW s of the glass sample can be determined. Recall that one mole of these CuO–vanadium phosphate glasses will have Avogadro number, N A , of molecules (A.2) N A = 1 2 V 4+ V total N V MW V 2 O 4 + 1 2 N V 1− V 4+ V total MW V 2 O 5 +N Cu MW CuO + 1 2 N P MW P 2 O 5 , where N P is the number of P ions per gram and is determined from Eq. (A.2) . Then (A.3) MW s =N A 1 2 V 4+ V total N V + 1 2 N V 1− V 4+ V total +N Cu + 1 2 N P , and the molar fraction of each constituent will be N V 2 O 4 = 1 2 V 4+ V total N V MW S N A N V 2 O 5 = 1 2 1− V 4+ V total N V MW S N A N CuO =N Cu MW S N A N P 2 O 5 = 1 2 N P MW S N A .

PY - 2000/2

Y1 - 2000/2

N2 - Vanadium phosphate glasses containing CuO with the chemical composition [(V2O5)0.6-x(P2O5)0.4(CuO) x], where x = 0.0, 0.1, 0.2 and 0.3, have been prepared and investigated by X-ray photoelectron spectroscopy (XPS) and magnetization measurements. The core-level binding energies of O 1s, P 2p, P 2s, Cu 2p and V 2p have been measured with the P 2p and P 2s peaks shifting by about 2 eV towards lower binding energies in the CuO-vanadium phosphate glasses from their values in P2O5, while the V 2p peaks shift by approximately 0.3 eV towards lower binding energies from V2O5 and the Cu 2p peaks shift by approximately 0.8 eV towards higher binding energies from CuO. These shifts can be accounted for by changes in the next-nearest neighbor environment around the P, Cu and V atoms and the reduction in the valence state of the Cu and V ions. The O 1s spectrum is fitted to two peaks and the variation in the ratio of the peak areas is discussed in terms of the local structure as well. In addition, the Cu 2p3/2 and Cu 2p1/2 peak show doublet structures in the XPS spectra which are associated with the presence of both Cu+ and Cu2+ in these glasses; although the XPS results indicate that more than 90% of the Cu ions exist in the Cu2+ state. Likewise a multivalent state for the V ions is indicated by an asymmetry and broadening in the V 2p spectra as the CuO concentration in the glasses increases. This tendency is also observed in the magnetic susceptibility results as the ratios V5+/Vtotal determined from XPS are in qualitative agreement with those determined by using the susceptibility measurements combined with inductively coupled plasma (ICP) spectroscopy results. Furthermore the susceptibility data appear to follow a Curie-Weiss behavior (χ = C/(T-θ)) for temperatures above approximately 40 K with negative Curie temperatures indicating that the predominate magnetic interactions between the Cu2+-Cu2+ and Cu2+-V4+ exchange pairs are antiferromagnetic in nature.

AB - Vanadium phosphate glasses containing CuO with the chemical composition [(V2O5)0.6-x(P2O5)0.4(CuO) x], where x = 0.0, 0.1, 0.2 and 0.3, have been prepared and investigated by X-ray photoelectron spectroscopy (XPS) and magnetization measurements. The core-level binding energies of O 1s, P 2p, P 2s, Cu 2p and V 2p have been measured with the P 2p and P 2s peaks shifting by about 2 eV towards lower binding energies in the CuO-vanadium phosphate glasses from their values in P2O5, while the V 2p peaks shift by approximately 0.3 eV towards lower binding energies from V2O5 and the Cu 2p peaks shift by approximately 0.8 eV towards higher binding energies from CuO. These shifts can be accounted for by changes in the next-nearest neighbor environment around the P, Cu and V atoms and the reduction in the valence state of the Cu and V ions. The O 1s spectrum is fitted to two peaks and the variation in the ratio of the peak areas is discussed in terms of the local structure as well. In addition, the Cu 2p3/2 and Cu 2p1/2 peak show doublet structures in the XPS spectra which are associated with the presence of both Cu+ and Cu2+ in these glasses; although the XPS results indicate that more than 90% of the Cu ions exist in the Cu2+ state. Likewise a multivalent state for the V ions is indicated by an asymmetry and broadening in the V 2p spectra as the CuO concentration in the glasses increases. This tendency is also observed in the magnetic susceptibility results as the ratios V5+/Vtotal determined from XPS are in qualitative agreement with those determined by using the susceptibility measurements combined with inductively coupled plasma (ICP) spectroscopy results. Furthermore the susceptibility data appear to follow a Curie-Weiss behavior (χ = C/(T-θ)) for temperatures above approximately 40 K with negative Curie temperatures indicating that the predominate magnetic interactions between the Cu2+-Cu2+ and Cu2+-V4+ exchange pairs are antiferromagnetic in nature.

UR - https://www.scopus.com/pages/publications/0033882443

U2 - 10.1016/S0022-3093(99)00700-0

DO - 10.1016/S0022-3093(99)00700-0

M3 - Article

AN - SCOPUS:0033882443

SN - 0022-3093

VL - 262

SP - 66

EP - 79

JO - Journal of Non-Crystalline Solids

JF - Journal of Non-Crystalline Solids

IS - 1

ER -

X-ray photoelectron spectroscopy (XPS) and magnetic susceptibility studies of copper-vanadium phosphate glasses

Abstract

Bibliographical note

ASJC Scopus subject areas

Access to Document

Fingerprint

Cite this