Optical and X-ray photoelectron spectroscopy of PbGeO3 and Pb5Ge3O11 single crystals

Abstract

Pb 5 Ge 3 O 11 crystals are found to exhibit pale yellow colouration while PbGeO 3 are colourless. X-ray photoelectron spectroscopy (XPS) measurements show lead deficiency in both the crystals. The results also reveal a stronger ionic character for PbGeO 3 as compared to Pb 5 Ge 3 O 11 crystal. The binding energy of Ge3d core level in the case of Pb 5 Ge 3 O 11 crystal is found to be smaller than the binding energy of germanium oxide, thereby indicating the incomplete oxidation of Ge ions in the crystal lattice. On gamma ray irradiation, the transmission of both the crystals is observed to deteriorate uniformly over the entire wavelength range, which has been attributed to the oxidation of some of the lattice Pb ions. On gamma irradiation the changes observed in O1s core level energies for both the crystals are seen to be consistent with the changes noted in the Pb4f 7/2 and Ge3d spectra. Interestingly, the results reveal oxidation of surface Ge atoms with atmospheric oxygen under gamma irradiation.

Pb5(GeO4)(Ge2O7) and Pb3.32Ca1.68(GeO4)(Ge2O7): Two Nonlinear Optical Germanates Induced by Diverse PbOx Polyhedra

“…Apart from the above lead germanates, compounds including PbGeO 3 , Pb 3 (GeO 5 ), Pb 5 (GeO 4 )­O 3 , Pb 11 (Ge 3 O 17 ), PbGe 3 O 7 , Pb­(Ge 4 O 9 ), and Pb 15 Ge 9 O 33 in a Pb–O–Ge ternary system have also been investigated (Table S5). There are three types of structures ( P 2/ c , Pm 3̅ m , and R 3̅) with the chemical formula of PbGeO 3 .…”

Ultrathin Hexagonal 2D Co2GeO4 Nanosheets: Excellent Li-Storage Performance and ex Situ Investigation of Electrochemical Mechanism

“…The high resolution spectra of Ge 3d shows an intense peak centered at 32 eV, which is usually a location for germanium oxide and consistent with the results for Ge(IV) in previously reported germanate. 26,27 Co 2p spectrum shows two main peaks centered at 781.3 and 797.2 eV, corresponding to Co 2p 3/2 and Co 2p 1/2 , respectively. It also could be seen that each main peak is accompanied by a shakeup satellite peak (787.3, 803.6 eV), which is a fingerprint to Co 2+ , indicating Co element in the nanosheets has +2 valence.…”

Enhancement in physical properties of Pb-Based Perovskite Oxides ($PbGeO_{3}$): Ab initio Calculation

“…In addition, the P bGeO 3 perovskite crystallizes in cubic structure which is reported in experimental and theoretical works [20]. Using X-ray photoelectron spectroscopy, they have calculated the binding energy of the P bGeO 3 and P b 5 Ge 3 O 11 phases and showed their optical transmission characteristics [11]. Other researchers showed that P bGeO 3 is considered an interesting choice for lithium batteries [21,22].…”

“…The exploitation of these materials mainly depends on their flexible structure, variable formula, and also their various properties [7,8]. Consequently, a lot of experimental and theoretical studies have proved that the perovskite oxides family has unique physical properties like photoelectric [9], magnetic [10], ferroelectric [11],.. etc.…”