A calorimetric investigation of polymorphism in a layered perovskite: KAlF4

White, Mary Anne; Wagner, Brian D.

doi:10.1016/0021-9614(86)90135-7

Cited by 3 publications

(1 citation statement)

References 12 publications

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“…The structure of tetragonal KAlF 4 belongs to a series of MAlF 4 (M = K, Rb, Tl or NH 4 ). [19] In these compounds, the endless AlF 6 octahedral compose the layers and occupy the four corners in the [001]. The structure of KAlF 4 is derived from that of the ideal TlAlF 4 by slightly rotating of the AlF 6 octahedra along the c-axis.…”

Section: Kalf4 Single Crystalmentioning

confidence: 99%

Growth of KAlF₄ and Na₅Al₃F₁₄ Aluminum Fluoride Single Crystals by Bridgman Method

Wang

Fang

et al. 2022

Crystal Research and Technology

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Highly transparent KAlF4 and Na5Al3F14 fluoride bulk single crystals in size of ≈Ф 50 mm × 10 mm are successfully grown for the first time by a modified Bridgman method. The physicochemical properties of the single crystals are investigated with the help of X‐ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG‐DTA), absorption spectrum, Fourier infrared spectroscopy, and Raman spectrum measurements. The KAlF4 and Na5Al3F14 phases of the obtained single crystals are determined from the results of XRD. The melting points of KAlF4 and Na5Al3F14 are measured to be ≈549 and ≈705 ℃ from their DTA curves. The maximum matrix phonon energies of KAlF4 and Na5Al3F14 single crystals are 544 and 530 cm–1 from their Raman spectra. The KAlF4 single crystal shows high transmittance from 2000 to 5500 nm, while Na5Al3F14 from 950 to 6000 nm. The energy gaps of KAlF4 and Na5Al3F14 are calculated to be 5.34 and 5.94 eV based on transmission spectra, respectively.

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Section: Kalf4 Single Crystalmentioning

confidence: 99%

Growth of KAlF₄ and Na₅Al₃F₁₄ Aluminum Fluoride Single Crystals by Bridgman Method

Wang

Fang

et al. 2022

Crystal Research and Technology

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Design of Layer‐Structured KAlF₄:Yb/Er for Pressure‐Enhanced Upconversion Luminescence

Zhang

Gao

Jiang

et al. 2019

Advanced Optical Materials

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anticounterfeiting, as well as bioimaging, biodetection, and thermal dynamic therapy. [7][8][9][10][11][12][13][14][15][16] In order to satisfy various functional parameters, large amount of efforts have been invested aiming to produce upconversion luminescence with expected characteristics in terms of the position, intensity, and lifetime of the emission bands, via suitable manipulations assisted by external stimuli, including electric field, magnetic field, temperature, mechanical force, as well as hydrostatic pressure. [17] Indeed, Hao et al. achieved a 2.7-fold upconversion luminescence enhancement by applying electric field on Yb 3+ / Er 3+ -doped epitaxially grown ferroelectric BaTiO 3 thin film, [18] Qiu et al. reported obvious luminescence enhancement under magnetic field in Yb 3+ /Ho 3+ -doped NaYF 4 nanoparticles, [19] Carlos et al. fabricated nanothermometers for precise and remote temperature sensing by taking advantage of temperature-induced upconversion luminescence emission, [20,21] and Xu et al. utilized mechanical luminescence generated by the fracture of constructions such as bridge, concrete wall, and buildings to monitor the status of constructions. [22,23] Compared to the above endeavors, hydrostatic pressure could offer unique merits to regulate and explore the luminescent properties, especially of upconversion luminescent materials, which is growing as a prevalent topic. [24][25][26] The tunable hydrostatic pressure can be utilized not only to probe the crystal structure and coordination bonding information of luminescent materials, but also to influence the electronic state and/or crystal field symmetry of luminescent ions. [27,28] This helps unveil the relationship between upconversion luminescent properties and crystal lattice variation of hosts, which provides direct insights in search of suitable crystal structures with improved performance for various purposes. [29] In addition, pressure-induced upconversion emission changes have wide applications in health monitoring, bioimaging, intelligent signature, optical sensors, nanomanometry, nanothermometry, [24,[30][31][32][33][34] as well as real-time monitoring of the working status of constructions via special coatings. [35][36][37][38] However, majority of such studies focused on downshifting luminescence and very limited examples targeted at upconversion emission whereas unfortunately, the unwanted decreased luminescence intensities are usually obtained under pressure. [24,25,34] The reason might be due to the Promising applications of downshifting mechanoluminescence have raised wide research enthusiasms in the past decades. However, weakened upconversion luminescence is usually obtained in lanthanide-doped materials under hydrostatic pressures. In layer-structured KAlF 4 , the z-axis has smaller elastic constant than that of the x-or y-axis, which can effectively tolerate high pressure influence on the coordination environment of luminescent ions by reducing the inter-layer distance and lead to enhanced upconversion luminescence. Ind...

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Librations and ordering in NH₄AIF₄. A heat capacity study

et al. 1990

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A calorimetric investigation of polymorphism in a layered perovskite: KAlF4

Cited by 3 publications

References 12 publications

Growth of KAlF₄ and Na₅Al₃F₁₄ Aluminum Fluoride Single Crystals by Bridgman Method

Growth of KAlF₄ and Na₅Al₃F₁₄ Aluminum Fluoride Single Crystals by Bridgman Method

Design of Layer‐Structured KAlF₄:Yb/Er for Pressure‐Enhanced Upconversion Luminescence

Librations and ordering in NH₄AIF₄. A heat capacity study

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A calorimetric investigation of polymorphism in a layered perovskite: KAlF4

Cited by 3 publications

References 12 publications

Growth of KAlF4 and Na5Al3F14 Aluminum Fluoride Single Crystals by Bridgman Method

Growth of KAlF4 and Na5Al3F14 Aluminum Fluoride Single Crystals by Bridgman Method

Design of Layer‐Structured KAlF4:Yb/Er for Pressure‐Enhanced Upconversion Luminescence

Librations and ordering in NH4AIF4. A heat capacity study

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Growth of KAlF₄ and Na₅Al₃F₁₄ Aluminum Fluoride Single Crystals by Bridgman Method

Growth of KAlF₄ and Na₅Al₃F₁₄ Aluminum Fluoride Single Crystals by Bridgman Method

Design of Layer‐Structured KAlF₄:Yb/Er for Pressure‐Enhanced Upconversion Luminescence

Librations and ordering in NH₄AIF₄. A heat capacity study