Ein mit Aragonit isotypes Cerborat

Weidelt, J.; Bambauer, H. U.

doi:10.1007/bf00600458

Cited by 20 publications

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“…The metaborates g-Ce(BO 2 ) 3 and d-Ce(BO 2 ) 3 could firstly be synthesized in our group under high-pressure/high-temperature conditions, namely 7.5 GPa/1000 C for g-Ce(BO 2 ) 3 and 3.5 GPa/1050 C for d-Ce(BO 2 ) 3 . In contrast to the a-metaborate, the crystal structures of g-Ce(BO 2 ) 3 and d-Ce(BO 2 ) 3 are exclusively built up from BO 4 tetrahedra, according to the pressurecoordination rule [13]. Recently, Hinteregger et al discovered Ce 4 B 14 O 27 , which was synthesized under high-pressure/high-temperature conditions of 2.6 GPa and 750 C starting from the oxides and CeF 3 as a flux [10].…”

Section: Introductionmentioning

confidence: 96%

“…Their crystal structures are built up exclusively from triangular BO 3 groups except for p-CeBO 3 , which exhibits only BO 4 tetrahedra and was synthesized at elevated pressure of 2 GPa. Due to the fact that p-ErBO 3 crystallizes in the monoclinic pseudowollastonite-type structure, space group C2/c, exhibiting isolated three-membered rings of corner-sharing BO 4 tetrahedra, which are stacked in a shifted arrangement [12], we presume that pCeBO 3 exhibits the same isotypic structure. Crystals of the metaborate a-Ce(BO 2 ) 3 were synthesized by Goriounova et al in a covered platinum crucible at 1100 C by slow cooling to 900 C. It crystallizes in the monoclinic space group I2/a being a member of the isostructural series a-RE(BO 2 ) 3 (RE ¼ La--Nd, Sm--Tb) exhibiting corner-sharing BO 3 and BO 4 groups.…”

Section: Introductionmentioning

confidence: 98%

“…Due to the fact that p-ErBO 3 crystallizes in the monoclinic pseudowollastonite-type structure, space group C2/c, exhibiting isolated three-membered rings of corner-sharing BO 4 tetrahedra, which are stacked in a shifted arrangement [12], we presume that pCeBO 3 exhibits the same isotypic structure. Crystals of the metaborate a-Ce(BO 2 ) 3 were synthesized by Goriounova et al in a covered platinum crucible at 1100 C by slow cooling to 900 C. It crystallizes in the monoclinic space group I2/a being a member of the isostructural series a-RE(BO 2 ) 3 (RE ¼ La--Nd, Sm--Tb) exhibiting corner-sharing BO 3 and BO 4 groups. The metaborates g-Ce(BO 2 ) 3 and d-Ce(BO 2 ) 3 could firstly be synthesized in our group under high-pressure/high-temperature conditions, namely 7.5 GPa/1000 C for g-Ce(BO 2 ) 3 and 3.5 GPa/1050 C for d-Ce(BO 2 ) 3 .…”

Section: Introductionmentioning

confidence: 98%

“…These are the orthoborates p-CeBO 3 , l-CeBO 3 , n-CeBO 3 , and H-CeBO 3 [1][2][3][4][5], the metaborates a-Ce(BO 2 ) 3 [1,6], g-Ce(BO 2 ) 3 [7,8], and d-Ce(BO 2 ) 3 [9], as well as the polyborates Ce 4 B 14 O 27 [10] and b-CeB 5 O 9 [11]. The orthoborates were synthesized utilizing standard methods of solid state syntheses, e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, Hinteregger et al discovered Ce 4 B 14 O 27 , which was synthesized under high-pressure/high-temperature conditions of 2.6 GPa and 750 C starting from the oxides and CeF 3 as a flux [10]. The structure consists of BO 3 groups as well as BO 4 tetrahedra, connected via common corners forming a three-dimensional framework containing three-, four-, and ninemembered borate rings. With b-REB 5 …”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Ce2B8O15: High-pressure synthesis and crystal structure determination of a rare-earth polyborate exhibiting a new “Fundamental Building Block”

Glätzle

Heymann

Huppertz

2013

Zeitschrift Für Kristallographie - Crystalline Materials

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show abstract

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Ce2B8O15: High-pressure synthesis and crystal structure determination of a rare-earth polyborate exhibiting a new “Fundamental Building Block”

Glätzle

Heymann

Huppertz

2013

Zeitschrift Für Kristallographie - Crystalline Materials

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Pr(BO2)3 und PrCl(BO2)2: Zwei meta-Borate des Praseodyms im Vergleich

Sieke

Nikelski

Schleid

2002

Z. anorg. allg. Chem.

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-009Pr(BO 2 ) 3 and PrCl(BO 2 ) 2 : Two Praseodymium meta-Borates in Comparison.-Single crystals of PrCl(BO 2 ) 2 (I) are obtained from the reaction of Pr 6 O 11 and PrCl 3 with excess B 2 O 3 (evacuated quartz tube, 850 • C, 7 d). The addition of NaCl as fluxing agent results in the formation of single crystals of Pr(BO 2 ) 3 (II) as the main product. (I) crystallizes in the triclinic space group P1 with Z = 2 and contains zigzag chains of corner-sharing BO 3 triangles. Pr 3+ is coordinated by three Cl − and seven O 2− anions forming a tetracapped trigonal prism. In the structure of compound (II) (monoclinic, space group C2/c, Z = 4) the boron atoms are present in both trigonal planar and tetrahedral oxygen coordination. The two types of polyhedra form chains via common corners. The coordination sphere of the Pr atoms is a bicapped square antiprism formed by ten O atoms.

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Beyond the Energy Gap Law: The Influence of Selection Rules and Host Compound Effects on Nonradiative Transition Rates in Boltzmann Thermometers

Netzsch

Hämmer

Turgunbajew

et al. 2022

Advanced Optical Materials

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range from biothermal imaging, [5,6] temperature monitoring in catalysis, [7][8][9][10] microelectronics, [11] or molecular logics [12] to the investigation of fundamental thermodynamic phenomena [13] at the micro-and nanoscale. One of the conceptually simplest ways of optical temperature sensing, also in terms of the required setup, is the exploitation of the luminescence intensity ratio (LIR) of two emission bands due to radiative transitions from two thermally coupled excited levels of an ensemble of non-interacting ions. In case of efficient thermal coupling between these levels by (multi) phonon transitions, the LIR follows Boltzmann's law. [14] Trivalent lanthanoid ions with the rich energy level structure arising from their partially filled 4f n (n = 1-13) configuration are primary representatives for this type of luminescence thermometry, with Er 3+ and its green-emitting 2 H 11/2 and 4 S 3/2 levels being the most prominent examples. [7,15] Boltzmann-type equilibrium between the two excited levels critically depends on the interplay between the depopulating radiative decay and the nonradiative multiphonon thermalization pathways. [14,16] The rate-determining step is the Apart from the energy gap law, control parameters over nonradiative transitions are so far only scarcely regarded. In this work, the impact of both covalence of the lanthanoid-ligand bond and varying bond distance on the magnitude of the intrinsic nonradiative decay rate between the excited 6 P 5/2 and 6 P 7/2 spin-orbit levels of Gd 3+ is investigated in the chemically related compounds Y 2 [B 2 (SO 4 ) 6 ] and LaBO 3 . Analysis of the temperature-dependent luminescence spectra reveals that the intrinsic nonradiative transition rates between the excited 6 P J ( J = 5/2, 7/2) levels are of the order of only 10 ms −1 (Y 2 [B 2 (SO 4 ) 6 ]:Gd 3+ : 8.9 ms −1 ; LaBO 3 :Gd 3+ : 10.5 ms −1 ) and differ due to the different degree of covalence of the GdO bonds in the two compounds. Comparison to the established luminescent Boltzmann thermometer Er 3+ reveals, however, that the nonradiative transition rates between the excited levels of Gd 3+ are over three orders of magnitude slower despite a similar energy gap and the presence of a single resonant phonon mode. This hints to a fundamental magnetic dipolar character of the nonradiative coupling in Gd 3+ . These findings can pave a way to control nonradiative transition rates and how to tune the dynamic range of luminescent Boltzmann thermometers.

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Ein mit Aragonit isotypes Cerborat

Cited by 20 publications

References 1 publication

Ce2B8O15: High-pressure synthesis and crystal structure determination of a rare-earth polyborate exhibiting a new “Fundamental Building Block”

Ce2B8O15: High-pressure synthesis and crystal structure determination of a rare-earth polyborate exhibiting a new “Fundamental Building Block”

Pr(BO2)3 und PrCl(BO2)2: Zwei meta-Borate des Praseodyms im Vergleich

Beyond the Energy Gap Law: The Influence of Selection Rules and Host Compound Effects on Nonradiative Transition Rates in Boltzmann Thermometers

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