Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure
CaMoO4- and SrMoO4-based scheelite-type phases are noteworthy functional materials, whose properties strongly correlate with their structure. This work is devoted to La- or Bi-doped scheelite-type molybdates. The purpose of the present study is to quantify the effect of isolated electron pairs of bi...
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| Format: | Article |
| Language: | English |
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Uralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. Elʹcina
2023-12-01
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| Series: | Chimica Techno Acta |
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| Online Access: | https://journals.urfu.ru/index.php/chimtech/article/view/7170 |
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| author | Zoya A. Mikhaylovskaya Alexandra V. Klimova Sofia A. Petrova Elizaveta A. Pankrushina Elena S. Buyanova |
| author_facet | Zoya A. Mikhaylovskaya Alexandra V. Klimova Sofia A. Petrova Elizaveta A. Pankrushina Elena S. Buyanova |
| author_sort | Zoya A. Mikhaylovskaya |
| collection | DOAJ |
| description | CaMoO4- and SrMoO4-based scheelite-type phases are noteworthy functional materials, whose properties strongly correlate with their structure. This work is devoted to La- or Bi-doped scheelite-type molybdates. The purpose of the present study is to quantify the effect of isolated electron pairs of bismuth on the distortion of the structure and related properties. Conventional solid-state technology was used for the synthesis of (Ca/Sr)1–3xLa2xФxMoO4 and Sr1–3xBi2xФxMoO4, (0.025≤ x ≤ 0.275). The structure was investigated by X-ray powder diffraction and Raman spectroscopy. Rates of structure distortion were characterised by the analysis of the autocorrelation function (AAF) of Raman spectra. Energy gaps were calculated by the Kubelka-Munk method. The conductivity was studied with a.c. impedance spectroscopy. For (Ca/Sr)1−3x(Bi/La)2xФxMoO4 series 0.025 ≤ x ≤ 0.15 compositions show a basic defect scheelite structure, while 0.15 x ≤ 0.225 compositions of Bi-doped samples exhibit tetragonal supercells. The chemical compression of unit cell is more evident in the case of Bi-doping, indicating the preferred orientation of the isolated electron pairs. The distortion of MoO4 polyhedra showed by AAF was more significant for Sr1−3xBi2xФxMoO4 than for Sr1−3xLa2xФxMoO4, the Δcorr parameters for Bi-doped compositions were almost double in comparison with La-doped one in the range of 50–600 cm–1 of the Raman shift. The «critical» x = 0.15 point was also clearly indicated by Δcorr parameter. The AAF of the Raman spectra of solid oxides was shown to be a good tool for prediction of properties and points of phase transitions in solid oxides. |
| first_indexed | 2024-03-08T14:27:39Z |
| format | Article |
| id | doaj.art-f5b54d21a7404f7bb21ec2b75c9e3be8 |
| institution | Directory Open Access Journal |
| issn | 2411-1414 |
| language | English |
| last_indexed | 2024-03-08T14:27:39Z |
| publishDate | 2023-12-01 |
| publisher | Uralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. Elʹcina |
| record_format | Article |
| series | Chimica Techno Acta |
| spelling | doaj.art-f5b54d21a7404f7bb21ec2b75c9e3be82024-01-12T19:40:07ZengUralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. ElʹcinaChimica Techno Acta2411-14142023-12-0110410.15826/chimtech.2023.10.4.115100Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structureZoya A. Mikhaylovskaya0Alexandra V. Klimova1Sofia A. Petrova2Elizaveta A. Pankrushina3Elena S. Buyanova4Zavaritsky Institute of Geology and Geochemistry, UB RASUral Federal UniversityInstitute of Metallurgy, UB RASZavaritsky Institute of Geology and Geochemistry, UB RASUral Federal UniversityCaMoO4- and SrMoO4-based scheelite-type phases are noteworthy functional materials, whose properties strongly correlate with their structure. This work is devoted to La- or Bi-doped scheelite-type molybdates. The purpose of the present study is to quantify the effect of isolated electron pairs of bismuth on the distortion of the structure and related properties. Conventional solid-state technology was used for the synthesis of (Ca/Sr)1–3xLa2xФxMoO4 and Sr1–3xBi2xФxMoO4, (0.025≤ x ≤ 0.275). The structure was investigated by X-ray powder diffraction and Raman spectroscopy. Rates of structure distortion were characterised by the analysis of the autocorrelation function (AAF) of Raman spectra. Energy gaps were calculated by the Kubelka-Munk method. The conductivity was studied with a.c. impedance spectroscopy. For (Ca/Sr)1−3x(Bi/La)2xФxMoO4 series 0.025 ≤ x ≤ 0.15 compositions show a basic defect scheelite structure, while 0.15 x ≤ 0.225 compositions of Bi-doped samples exhibit tetragonal supercells. The chemical compression of unit cell is more evident in the case of Bi-doping, indicating the preferred orientation of the isolated electron pairs. The distortion of MoO4 polyhedra showed by AAF was more significant for Sr1−3xBi2xФxMoO4 than for Sr1−3xLa2xФxMoO4, the Δcorr parameters for Bi-doped compositions were almost double in comparison with La-doped one in the range of 50–600 cm–1 of the Raman shift. The «critical» x = 0.15 point was also clearly indicated by Δcorr parameter. The AAF of the Raman spectra of solid oxides was shown to be a good tool for prediction of properties and points of phase transitions in solid oxides.https://journals.urfu.ru/index.php/chimtech/article/view/7170strontium bismuth molybdatecalcium bismuth molybdatex-ray diffractionraman spectroscopyautocorrelation functionconductivityenergy gap |
| spellingShingle | Zoya A. Mikhaylovskaya Alexandra V. Klimova Sofia A. Petrova Elizaveta A. Pankrushina Elena S. Buyanova Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure Chimica Techno Acta strontium bismuth molybdate calcium bismuth molybdate x-ray diffraction raman spectroscopy autocorrelation function conductivity energy gap |
| title | Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure |
| title_full | Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure |
| title_fullStr | Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure |
| title_full_unstemmed | Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure |
| title_short | Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure |
| title_sort | comparative characteristic of bi and la doped ca sr moo4 based materials with a defect scheelite type structure |
| topic | strontium bismuth molybdate calcium bismuth molybdate x-ray diffraction raman spectroscopy autocorrelation function conductivity energy gap |
| url | https://journals.urfu.ru/index.php/chimtech/article/view/7170 |
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