Crystal structural phase transition in CaCrO<sub>4</sub>under high pressure

Long, Youwen; Yang, Lingxiao; You, Shujie; Yu, Yanke; Yu, Richeng; Chen, Jin; Liu, Jing

doi:10.1088/0953-8984/18/8/008

Cited by 17 publications

(14 citation statements)

References 29 publications

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“…1). The zircon-scheelite-fergusonite sequence has been also recently predicted theoretically for YCrO 4 [17] and CaCrO 4 [18] and has been recently observed experimentally in YCrO 4 [19] and ZrSiO 4 [20]. Therefore, the systematics here presented can be useful for predicting post-scheelite phases in compounds isostructural to zircon.…”

Section: Systematics Of the Pressure-induced Phase Transitionssupporting

confidence: 77%

Crystal stability and pressure‐induced phase transitions in scheelite AWO₄ (A = Ca, Sr, Ba, Pb, Eu) binary oxides. II: Towards a systematic understanding

Manjón¹,

Errandonea

López-Solano

et al. 2006

Physica Status Solidi (b)

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Recent experimental measurements and ab initio calculations in scheelite CaWO 4 , SrWO 4 , BaWO 4 , PbWO 4 , EuWO 4 and YLiF 4 crystals reveal the existence of complex high-pressure phase diagrams, which present striking differences but also relevant similarities. In this work we show that the high-pressure structural sequence in the studied scheelites can be understood on the basis of the positions of the different ABX 4 compounds in Fukunaga and Yamaoka's diagram and in Bastide's diagram. Our study can help to understand the phase diagrams and high-pressure phase transitions occurring in ABX 4 compounds with scheelite, wolframite, fergusonite, zircon, or pseudoscheelite structures.

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Section: Systematics Of the Pressure-induced Phase Transitionssupporting

confidence: 77%

Crystal stability and pressure‐induced phase transitions in scheelite AWO₄ (A = Ca, Sr, Ba, Pb, Eu) binary oxides. II: Towards a systematic understanding

Manjón¹,

Errandonea

López-Solano

et al. 2006

Physica Status Solidi (b)

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“…Therefore, it could be concluded that the Cr 6+ ion was stably dispersed in the γ‐C 2 S local structure by substituting a Si 4+ site in a SiO 4 tetrahedron with a Ca vacancy at the first nearest‐neighboring position from the CrO 4 tetrahedron. In fact, the above‐modeled local structure of Cr ion in γ‐C 2 S resembles that of Cr ion in CaCrO 4 …”

Section: Resultsmentioning

confidence: 89%

“…In fact, the abovemodeled local structure of Cr ion in c-C 2 S resembles that of Cr ion in CaCrO 4 . 20 Consequently, the above first-principle calculation indicated that chromium ions could be stably distributed in c-C 2 S with a CaCrO 4 -like local structure. Furthermore, as previously shown in Fig.…”

Section: (3) Local Structure Modeling Of Cr Ions In Dicalcium Silicatmentioning

confidence: 89%

Formation and Local Structure Analysis of High‐Valence Chromium Ion in Dicalcium Silicate

et al. 2016

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Dicalcium silicate (2CaO·SiO2) is a typical silicate compound that exists even at elevated temperatures. Different types of elements can be dispersed in dicalcium silicate to form a solid solution phase. However, the dispersion behavior of transition elements that can display different ionic valences is not well understood. Herein, we investigate the local structure of chromium ions dispersed in dicalcium silicate of different phase states under inert and air atmospheres using Cr K‐edge X‐ray absorption near‐edge structure (XANES) spectroscopy and first‐principle calculations. The measured XANES spectra indicated that Cr ions exist as high‐valence states when dispersed in dicalcium silicate in air atmosphere. Specifically, Cr6+ ions were detected in γ‐dicalcium silicate, which was prepared by annealing a mixture of 2CaO·SiO2 and Cr2O3 at 973 K in air atmosphere. In addition, the XANES spectra obtained via first‐principle calculations revealed that Cr ions, with high‐valence states between Cr4+ and Cr6+, in dicalcium silicate, occupy the tetrahedral Si4+ sites.

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“…In particular, unusual isomorphic transitions have been detected in PbCrO 3 (6 GPa) [2] and PbCrO 4 (4 GPa) [7]. In the last compound, a second transition has been reported at 12 GPa [7].…”

Section: Introductionmentioning

confidence: 91%

Tuning the band gap of PbCrO4 through high-pressure: Evidence of wide-to-narrow semiconductor transitions

Errandonea

Bandiello

Segura

et al. 2014

Journal of Alloys and Compounds

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Abstract:The electronic transport properties and optical properties of lead(II) chromate (PbCrO 4 ) have been studied at high pressure by means of resistivity, Hall-effect, and optical-absorption measurements. Band-structure first-principle calculations have been also performed. We found that the low-pressure phase is a direct band-gap semiconductor (Eg = 2.3 eV) that shows a high resistivity. At 3.5 GPa, associated to a structural phase transition, a band-gap collapse takes place, becoming Eg = 1.8 eV. At the same pressure the resistivity suddenly decreases due to an increase of the carrier concentration. In the HP phase, PbCrO 4 behaves as an n-type semiconductor, with a donor level probably associated to the formation of oxygen vacancies. At 15 GPa a second phase transition occurs to a phase with Eg = 1.2 eV. In this phase, the resistivity increases as pressure does probably due to the self-compensation of donor levels and the augmentation of the scattering of electrons with ionized impurities. In the three phases the band gap red shifts under compression. At 20 GPa, Eg reaches a value of 0.8 eV, behaving PbCrO 4 as a narrow-gap semiconductor.

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Crystal structural phase transition in CaCrO₄under high pressure

Cited by 17 publications

References 29 publications

Crystal stability and pressure‐induced phase transitions in scheelite AWO₄ (A = Ca, Sr, Ba, Pb, Eu) binary oxides. II: Towards a systematic understanding

Crystal stability and pressure‐induced phase transitions in scheelite AWO₄ (A = Ca, Sr, Ba, Pb, Eu) binary oxides. II: Towards a systematic understanding

Formation and Local Structure Analysis of High‐Valence Chromium Ion in Dicalcium Silicate

Tuning the band gap of PbCrO4 through high-pressure: Evidence of wide-to-narrow semiconductor transitions

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Crystal structural phase transition in CaCrO4under high pressure

Cited by 17 publications

References 29 publications

Crystal stability and pressure‐induced phase transitions in scheelite AWO4 (A = Ca, Sr, Ba, Pb, Eu) binary oxides. II: Towards a systematic understanding

Crystal stability and pressure‐induced phase transitions in scheelite AWO4 (A = Ca, Sr, Ba, Pb, Eu) binary oxides. II: Towards a systematic understanding

Formation and Local Structure Analysis of High‐Valence Chromium Ion in Dicalcium Silicate

Tuning the band gap of PbCrO4 through high-pressure: Evidence of wide-to-narrow semiconductor transitions

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Crystal structural phase transition in CaCrO₄under high pressure

Crystal stability and pressure‐induced phase transitions in scheelite AWO₄ (A = Ca, Sr, Ba, Pb, Eu) binary oxides. II: Towards a systematic understanding

Crystal stability and pressure‐induced phase transitions in scheelite AWO₄ (A = Ca, Sr, Ba, Pb, Eu) binary oxides. II: Towards a systematic understanding