Phase transitions in Sr-containing phosphates and vanadates with β-Ca3(PO4)2-related structures

Belik, Alexei А.; Azuma, Masaki; Takano, Mikio

doi:10.1016/j.ssi.2004.02.061

Cited by 10 publications

(7 citation statements)

References 7 publications

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“…Structure Refinement of High-Temperature Phase of Sr 9 Fe(PO 4 ) 7 . The dependence of the lattice parameters on temperature in Sr 9 Fe(PO 4 ) 7 was very similar to that in Sr 9 -Tb(PO 4 ) 7 12 and Sr 9 In(PO 4 ) 7 . 13 The lattice parameters of Sr 9 -Fe(PO 4 ) 7 gradually changed with temperature through the phase transition temperature.…”

Section: Resultssupporting

confidence: 58%

“…Figure depicts the dependence of permittivity on temperature in Sr 9 Fe(PO 4 ) 7 at 0.1 and 1 MHz. A clear anomaly was observed at about 740 K. The broad maximum on the ε versus T curves in Sr 9 Fe(PO 4 ) 7 was less pronounced than that in Sr 9 In(PO 4 ) 7 . Nevertheless, the dielectric data suggest that Sr 9 Fe(PO 4 ) 7 and Sr 9 In(PO 4 ) 7 undergo the same type of antiferroelectric-paraelectric transitions.…”

Section: Resultsmentioning

confidence: 88%

“…A clear anomaly was observed at about 740 K. The broad maximum on the versus T curves in Sr 9 Fe(PO 4 ) 7 was less pronounced than that in Sr 9 In(PO 4 ) 7 . 12 Nevertheless, the dielectric data suggest that Sr 9 Fe(PO 4 ) 7 and Sr 9 In(PO 4 ) 7 undergo the same type of antiferroelectric-paraelectric transitions. Whereas no anomaly was found in the DTA curve of Sr 9 Fe(PO 4 ) 7 , a steplike anomaly was detected at 740 K in its DSC curves (inset of Figure 4).…”

Section: Resultsmentioning

confidence: 93%

“…Strontium phosphates, Sr 9 R(PO 4 ) 7 (R = Sc, Cr, Fe, Ga, In, Y, and Gd−Lu), with a structure closely related to those of β-Ca 3 (PO 4 ) 2 and Ca 9 Fe(PO 4 ) 7 , have recently been prepared and characterized. , An antiferroelectric-paraelectric phase transition at 773 K was found in Sr 9 In(PO 4 ) 7 .…”

Section: Introductionmentioning

confidence: 99%

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Redox Reactions in Strontium Iron Phosphates: Synthesis, Structures, and Characterization of Sr₉Fe(PO₄)₇ and Sr₉FeD(PO₄)₇

et al. 2005

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Physical and chemical properties of Sr9Fe(PO4)7 and Sr9FeD(PO4)7 were investigated by Mössbauer, infrared, and Raman spectroscopy, magnetization and dielectric measurements, differential scanning calorimetry, and thermal analysis. Sr9Fe(PO4)7 undergoes an antiferroelectric-paraelectric (AFE-PE) phase transition at T c = 740 K. Structure parameters of the AFE phase at 293 K were refined from time-of-flight (TOF) neutron powder diffraction data (space group C2/c; Z = 4; a = 14.4971(2) Å, b = 10.6005(13) Å, c = 17.9632(3) Å, and β = 112.5053(9)°), and those of the PE phase at 923 K from synchrotron X-ray powder diffraction data (space group R3̄m; Z = 3; a = 10.70473(13) Å and c = 19.8605(2) Å). Parts of Sr atoms and PO4 tetrahedra are highly disordered in the PE phase. Sr9FeD(PO4)7 was prepared by treating Sr9Fe(PO4)7 with D2 at 820 K. The incorporation of D atoms above T c kept the structure of the high-temperature modification of Sr9Fe(PO4)7. Therefore, Sr9FeD(PO4)7 is isotypic with the PE phase of Sr9Fe(PO4)7. Rietveld refinements from TOF neutron diffraction data and synchrotron XRD data of Sr9FeD(PO4)7 (at 293 K) on the basis of space group R3̄m gave lattice parameters a = 10.67744(13) Å and c = 19.5810(2) Å, making it possible to locate D atoms at two positions. Oxidation of Sr9FeD(PO4)7 in air above 673 K regenerated Sr9Fe(PO4)7. When Sr9FeD(PO4)7 was heated above 940 K in the absence of oxygen and when Sr9Fe(PO4)7 was treated by 5% H2 + 95% N2 above 1100 K, they decomposed to Sr2P2O7 and Sr9.333Fe1.167(PO4)7.

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Section: Resultssupporting

confidence: 58%

Section: Resultsmentioning

confidence: 88%

Section: Resultsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

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Redox Reactions in Strontium Iron Phosphates: Synthesis, Structures, and Characterization of Sr₉Fe(PO₄)₇ and Sr₉FeD(PO₄)₇

et al. 2005

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“…Детальное исследование сегнетоэлектрических характеристик при высокой температуре в этом семействе осложняется большой электропроводностью по ионам Ca 2+ . Это явление удается ограничить лишь в случае значительного замещения ионов Ca 2+ на существенно более крупные ионы Sr 2+ или Pb 2+ [3,4]. В настоящей работе изучено влияние замещения катионов кальция и свинца в ванадате Sr 9 Tm(VO 4 ) 7 , имеющего, по предварительным данным, сегнетоэлектрическое фазовое превращение вблизи температуры 950 K [3].…”

Section: Introductionunclassified

Сегнетоэлектрические фазовые переходы в Sr-=SUB=-9-=/SUB=-Tm(VO_4)-=SUB=-7-=/SUB=- при замещении стронция на кальций и свинец

Барышникова¹,

Дейнеко²,

Потаенко³

et al. 2020

Физика Твердого Тела

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By solid-phase synthesis at 1373 K in Sr9-xMexTm (VO4)7 systems the solid solutions with Me = Ca (0≤ x≤2) and Me = Pb (0≤ x≤1) were obtained. Single-phase samples at room temperature are isostructural to the Ca3(VO4)2 ferroelectric (space group (sp.gr.) R3c, Z = 6). Substances are characterized by X-ray phase analysis (XRD), second optical harmonic generation (SHG), and dielectric spectroscopy. The intensity of the SHG signal change depending on the substitution cation and its concentration varies in the range of 30-50 units relative to the quartz standard. A reversible ferroelectric phase transition was found in the temperature range 850–960 K. The transition is accompanied by a sharp maximum in the temperature dependence of the dielectric constant. The absence of a SHG signal above the transition temperature indicates the centrosymmetry of the paraelectric phase.

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Sr2InV3O11 – New ceramic compound in Sr2V2O7–InVO4 system and its characteristic

Filipek

Agnieszka

Piz

2016

Ceramics International

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Phase transitions in Sr-containing phosphates and vanadates with β-Ca3(PO4)2-related structures

Cited by 10 publications

References 7 publications

Redox Reactions in Strontium Iron Phosphates: Synthesis, Structures, and Characterization of Sr₉Fe(PO₄)₇ and Sr₉FeD(PO₄)₇

Redox Reactions in Strontium Iron Phosphates: Synthesis, Structures, and Characterization of Sr₉Fe(PO₄)₇ and Sr₉FeD(PO₄)₇

Сегнетоэлектрические фазовые переходы в Sr-=SUB=-9-=/SUB=-Tm(VO_4)-=SUB=-7-=/SUB=- при замещении стронция на кальций и свинец

Sr2InV3O11 – New ceramic compound in Sr2V2O7–InVO4 system and its characteristic

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Phase transitions in Sr-containing phosphates and vanadates with β-Ca3(PO4)2-related structures

Cited by 10 publications

References 7 publications

Redox Reactions in Strontium Iron Phosphates: Synthesis, Structures, and Characterization of Sr9Fe(PO4)7 and Sr9FeD(PO4)7

Redox Reactions in Strontium Iron Phosphates: Synthesis, Structures, and Characterization of Sr9Fe(PO4)7 and Sr9FeD(PO4)7

Сегнетоэлектрические фазовые переходы в Sr-=SUB=-9-=/SUB=-Tm(VO_4)-=SUB=-7-=/SUB=- при замещении стронция на кальций и свинец

Sr2InV3O11 – New ceramic compound in Sr2V2O7–InVO4 system and its characteristic

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Redox Reactions in Strontium Iron Phosphates: Synthesis, Structures, and Characterization of Sr₉Fe(PO₄)₇ and Sr₉FeD(PO₄)₇

Redox Reactions in Strontium Iron Phosphates: Synthesis, Structures, and Characterization of Sr₉Fe(PO₄)₇ and Sr₉FeD(PO₄)₇