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Sánchez-Movellán I, Aramburu JA, Moreno M. Chemical Bonding, 10Dq Parameter and Superexchange in the Model Compound KNiF 3. Chemphyschem 2024; 25:e202400006. [PMID: 38573167 DOI: 10.1002/cphc.202400006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 04/03/2024] [Accepted: 04/03/2024] [Indexed: 04/05/2024]
Abstract
The cubic field splitting parameter, 10Dq, plays a central role in the ligand field theory on insulating transition metal compounds. Experimental data obtained in the last 50 years prove that 10Dq is highly dependent on changes of the metal-ligand distance, R, induced by chemical or applied pressures. Despite this fact has important consequences on optical and magnetic properties of such compounds, its actual origin is still controversial. Seeking to clarify that crucial issue, this work is focused on KNiF3, a reference system among insulating transition metal compounds. By means of first principles calculations we show that, contrary to what is usually thought, the R-dependence of 10Dq arises neither from the crystal field contribution nor from the covalent admixture of 3d(Ni) with valence 2p(F) orbitals. Indeed, we prove that it is mainly due to the residual covalency with deep 2s(F) orbitals, highly sensitive to R variations. As a salient feature the present calculations show that the 3d-2pσ and 3d-2pπ admixtures raise practically equal the energy of antibonding eg and t2g orbitals of NiF6 4- units in KNiF3 thus leading to a null contribution to 10Dq. This conclusion is not significantly altered when considering the change of covalency on passing from the ground state 3A2(t2g 6eg 2) to the excited state 3T2(t2g 5eg 3). The different influence of chemical bonding on the superexchange constant, J, and 10Dq is also discussed in a second step. It is pointed out that the strong dependence of J upon R can hardly be explained through the behavior of the 3d-2pσ covalency derived for a single NiF6 4- unit. For the sake of clarity, the meaning of 10Dq is also briefly analyzed.
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Affiliation(s)
- Inés Sánchez-Movellán
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Avenida de los Castros s/n, 39005, Santander, Spain
| | - José Antonio Aramburu
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Avenida de los Castros s/n, 39005, Santander, Spain
| | - Miguel Moreno
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Avenida de los Castros s/n, 39005, Santander, Spain
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2
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Dou C, Cai C, Song Z, Liu Q. Broadband Near-Infrared Sr 3Al 9.8SiO 20:0.2Cr Phosphor Realized by Crystallographic Site Engineering. Inorg Chem 2024; 63:902-908. [PMID: 38153042 DOI: 10.1021/acs.inorgchem.3c03990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Broadband near-infrared (NIR) phosphor-converted devices play a vital role in emerging applications of imaging, medicine, agriculture, etc. Herein, a series of economical broadband NIR-emitting Sr3Al10-xSiO20:xCr (SASO:xCr) phosphors with tunable bandwidths and emission peaks were realized by tailoring the Cr3+ doping concentration. The optimal Sr3Al9.8SiO20:0.2Cr (SASO:0.2Cr) phosphor exhibits a broadband emission with full width at half-maximum ∼ 140 nm, and the internal/external quantum efficiency and thermal stability of the SASO:0.2Cr were measured to be 68%/37% and 77%@380 K, respectively. An NIR phosphor-converted light-emitting diode (NIR pc-LED) device was fabricated by combining a blue LED chip with the SASO:0.2Cr phosphor. The applications of NIR pc-LED on plant growth promotion, night vision, and medical imaging were demonstrated. We reported an economical broadband NIR phosphor with multiple potential applications and highlighted the crystallographic site engineering strategy to explore broadband phosphors based on aluminates.
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Affiliation(s)
- Chao Dou
- The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Sciences and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Chuxin Cai
- The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Sciences and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhen Song
- The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Sciences and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Quanlin Liu
- The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Sciences and Engineering, University of Science and Technology Beijing, Beijing 100083, China
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3
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Buta CM, Radu MM, Mischie A, Zălaru CM, Ioniţă G, Ferbinteanu M. Experimental and computational characterization of structural and spectroscopic features of mixed ligand copper complexes-prototypes for square-pyramidal stereochemistry. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.06.046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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4
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Hunault MOJY, Harada Y, Miyawaki J, Wang J, Meijerink A, de Groot FMF, van Schooneveld MM. Direct Observation of Cr 3+ 3d States in Ruby: Toward Experimental Mechanistic Evidence of Metal Chemistry. J Phys Chem A 2018; 122:4399-4413. [PMID: 29660293 PMCID: PMC6023264 DOI: 10.1021/acs.jpca.8b00984] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
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The
role of transition metals in chemical reactions is often derived
from probing the metal 3d states. However, the relation between metal
site geometry and 3d electronic states, arising from multielectronic
effects, makes the spectral data interpretation and modeling of these
optical excited states a challenge. Here we show, using the well-known
case of red ruby, that unique insights into the density of transition
metal 3d excited states can be gained with 2p3d resonant inelastic
X-ray scattering (RIXS). We compare the experimental determination
of the 3d excited states of Cr3+ impurities in Al2O3 with 190 meV resolution 2p3d RIXS to optical absorption
spectroscopy and to simulations. Using the crystal field multiplet
theory, we calculate jointly for the first time the Cr3+ multielectronic states, RIXS, and optical spectra based on a unique
set of parameters. We demonstrate that (i) anisotropic 3d multielectronic
interactions causes different scaling of Slater integrals, and (ii)
a previously not observed doublet excited state exists around 3.35
eV. These results allow to discuss the influence of interferences
in the RIXS intermediate state, of core–hole lifetime broadenings,
and of selection rules on the RIXS intensities. Finally, our results
demonstrate that using an intermediate excitation energy between L3 and L2 edges allows measurement of the density
of 3d excited states as a fingerprint of the metal local structure.
This opens up a new direction to pump-before-destroy investigations
of transition metal complex structures and reaction mechanisms.
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Affiliation(s)
- Myrtille O J Y Hunault
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science , Utrecht University , 3584CG Utrecht , The Netherlands
| | - Yoshihisa Harada
- Institute for Solid State Physics , University of Tokyo , Kashiwa , Chiba 277-8581 , Japan
| | - Jun Miyawaki
- Institute for Solid State Physics , University of Tokyo , Kashiwa , Chiba 277-8581 , Japan
| | - Jian Wang
- Canadian Light Source Inc. , Saskatoon , Saskatchewan S7N 2V3 Canada
| | - Andries Meijerink
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science , Utrecht University , 3584CG Utrecht , The Netherland
| | - Frank M F de Groot
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science , Utrecht University , 3584CG Utrecht , The Netherlands
| | - Matti M van Schooneveld
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science , Utrecht University , 3584CG Utrecht , The Netherlands
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5
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Liu M, Wang X, Wei S, Hu H, Zhang R, Liu L. Cr-doped Fe2F5·H2O with open framework structure as a high performance cathode material of sodium-ion batteries. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.02.159] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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6
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Maalej O, Taktak O, Boulard B, Kammoun S. Study with Analytical Equations of Absorption Spectra Containing Interference Dips in Fluoride Glasses Doped with Cr3+. J Phys Chem B 2016; 120:7538-45. [DOI: 10.1021/acs.jpcb.6b03230] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- O. Maalej
- Institut
des Molécules et Matériaux du Mans, UMR CNRS 6283, Université du Maine, Av. O. Messiaen, 72085 Le Mans cedex 09, France
- Laboratoire
de Chimie Inorganique, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000, Sfax, Tunisia
| | - O. Taktak
- Laboratoire
de Physique Appliquée, Groupe de Physique des Matériaux
Luminescents, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000, Sfax, Tunisia
| | - B. Boulard
- Institut
des Molécules et Matériaux du Mans, UMR CNRS 6283, Université du Maine, Av. O. Messiaen, 72085 Le Mans cedex 09, France
| | - S. Kammoun
- Laboratoire
de Physique Appliquée, Groupe de Physique des Matériaux
Luminescents, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000, Sfax, Tunisia
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Singh P, Choudhuri I, Rai HM, Mishra V, Kumar R, Pathak B, Sagdeo A, Sagdeo PR. Fe doped LaGaO3: good white light emitters. RSC Adv 2016. [DOI: 10.1039/c6ra21693e] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Photoluminescence emission spectra from Fe doped LaGaO3. The luminescence due to ultra violet He–Cd laser is shown in the inset.
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Affiliation(s)
- Preetam Singh
- Material Research Laboratory
- Discipline of Physics & MEMS
- Indian Institute of Technology Indore
- Indore-453552
- India
| | - Indrani Choudhuri
- Discipline of Chemistry & MEMS
- Indian Institute of Technology Indore
- Indore-453552
- India
| | - Hari Mohan Rai
- Material Research Laboratory
- Discipline of Physics & MEMS
- Indian Institute of Technology Indore
- Indore-453552
- India
| | - Vikash Mishra
- Material Research Laboratory
- Discipline of Physics & MEMS
- Indian Institute of Technology Indore
- Indore-453552
- India
| | - Rajesh Kumar
- Material Research Laboratory
- Discipline of Physics & MEMS
- Indian Institute of Technology Indore
- Indore-453552
- India
| | - Biswarup Pathak
- Discipline of Chemistry & MEMS
- Indian Institute of Technology Indore
- Indore-453552
- India
| | - Archna Sagdeo
- Indus Synchrotron Utilization Division
- Raja Ramanna Center for Advanced Technology
- Indore-452013
- India
- Homi Bhabha National Institute
| | - P. R. Sagdeo
- Material Research Laboratory
- Discipline of Physics & MEMS
- Indian Institute of Technology Indore
- Indore-453552
- India
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García-Lastra JM, García-Fernández P, Barriuso MT, Aramburu JA, Moreno M. Sharp lines due to Cr³⁺ and Mn²⁺ impurities in insulators: going beyond the usual Tanabe-Sugano approach. J Phys Chem A 2014; 118:2377-84. [PMID: 24580411 DOI: 10.1021/jp5010067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This work is aimed at understanding the different behavior of optical sharp lines (corresponding to 10Dq-independent transitions) of Mn(2+) and Cr(3+) in normal and inverted perovskites that cannot be explained within the usual Tanabe-Sugano approach. In particular, we want to clarify why on passing from KMgF3:M to LiBaF3:M (M = Mn(2+), Cr(3+)) the energy, E((6)A1 → (4)A1), for Mn(2+) decreases by Δ = 1100 cm(-1), while Δ < 100 cm(-1) for the energy E((2)E →( 4)A2) corresponding to Cr(3+). The origin of this surprising difference in these model systems is clarified by writing the transition energies of MF6 complexes through the ten Coulomb and exchange integrals consistent with the cubic symmetry and not considered in the usual Tanabe-Sugano approach. It is shown that E((6)A1 → (4)A1) depends on exchange integrals K(3z(2) - r(2), xy) and K(x(2) - y(2), xy), while E((2)E → (4)A2) depends on K(xz, yz) where the two involved electrons display a π character. These exchange integrals have been calculated just considering a MF6 unit subject to the internal electric field due to the rest of the lattice ions. In addition to a reasonably reproduction of the main trends observed experimentally for the model systems, the present calculations prove that the exchange integrals are not related in a simple way to the covalency of involved orbitals. Particular attention is also paid to explain why the transitions, which are 10Dq-independent are less sensitive to the host lattice change than those which do depend on 10Dq. The present work shows that K(xz, yz) for Cr(3+) is particularly insensitive to the host lattice change and thus sheds light on the origin of the near independence of E((2)E → (4)A2) along the series of oxides doped with such an impurity .
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Affiliation(s)
- J M García-Lastra
- Center for Atomic-scale Materials Design, Department of Physics, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark
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9
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Aramburu JA, García-Fernández P, Barriuso MT, Moreno M. Transition metal complexes coupled to vacancies in oxides: origin of different properties of Cr3+ in MgO bounded to a <100> or <110> Mg2+ vacancy. J Phys Chem A 2013; 117:12642-7. [PMID: 24164414 DOI: 10.1021/jp409276p] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Despite the importance of vacancies over the properties of insulating oxides its influence on neighboring transition metal ions is far from being understood. This work is devoted to find the origin of various up to now unexplained properties of chromium bounded either to a <100> or a <110> Mg(2+) vacancy in MgO. In these model systems particular attention is paid to understand, by means of ab initio calculations, why the cubic field splitting parameter, 10Dq, is surprisingly 1600 cm(-1) higher for a <100> than for a <110> vacancy, a fact behind the suppression of the sharp (2)E → (4)A2 luminescence in the latter case. Our calculations, which reproduce the main experimental facts, prove that the average Cr(3+)-O(2-) distance is the same within 0.8% for both systems, and thus, the low 10Dq value for a <110> vacancy is shown to be due mainly to the electrostatic potential from the missing Mg(2+) ion, which increases the energy of antibonding t(2g) (∼xy, xz, yz) levels. By contrast, for a <100> Mg(2+) vacancy that potential provides a supplementary increase of the e(g) (∼x(2) - y(2), 3z(2 )- r(2)) level energy and thus of 10Dq. The existence of the (2)E → (4)A2 luminescence for Cr(3+)-doped MgO under perfect cubic symmetry or with a <100> vacancy is shown to be greatly helped by the internal electric field created by the rest of the lattice ions on the CrO6(9-) unit, whose importance is usually ignored. The present results underline the role of ab initio calculations for unveiling the subtle effects induced by a close vacancy on the properties of transition metal ions in oxides. At the same time they stress the failure of the empirical superposition model for deriving the equilibrium geometry of C4v and C2v centers in MgO:Cr(3+).
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Affiliation(s)
- J A Aramburu
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria , Avenida de los Castros s/n, 39005 Santander, Spain
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10
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Aramburu JA, García-Lastra JM, García-Fernández P, Barriuso MT, Moreno M. Cu2+ in Layered Compounds: Origin of the Compressed Geometry in the Model System K2ZnF4:Cu2+. Inorg Chem 2013; 52:6923-33. [DOI: 10.1021/ic400105z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- J. A. Aramburu
- Departamento de Ciencias de
la Tierra y Física de la Materia Condensada, Universidad de
Cantabria, Avenida de los Castros s/n, 39005 Santander, Spain
| | - J. M. García-Lastra
- Center for Atomic-Scale Materials
Design, Department of Physics, Technical University of Denmark, DK-2800
Kongens Lyngby, Denmark
| | - P. García-Fernández
- Departamento de Ciencias de
la Tierra y Física de la Materia Condensada, Universidad de
Cantabria, Avenida de los Castros s/n, 39005 Santander, Spain
| | - M. T. Barriuso
- Departamento
de Física
Moderna, Universidad de Cantabria, Avenida de los Castros s/n, 39005
Santander, Spain
| | - M. Moreno
- Departamento de Ciencias de
la Tierra y Física de la Materia Condensada, Universidad de
Cantabria, Avenida de los Castros s/n, 39005 Santander, Spain
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11
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Aramburu JA, García-Fernández P, García-Lastra JM, Barriuso MT, Moreno M. Colour due to Cr3+ ions in oxides: a study of the model system MgO:Cr3+. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:175501. [PMID: 23552342 DOI: 10.1088/0953-8984/25/17/175501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Seeking to understand why the cubic centre in MgO:Cr(3+) has the same 10Dq value as emerald, ab initio cluster and periodic supercell calculations have been performed. It is found that the equilibrium Cr(3+)-O(2-) distance, R, in MgO:Cr(3+) is equal to 2.03 Å and thus 0.06 Å higher than that measured for the emerald. Calculations carried out on the isolated CrO(6)(9-) complex at R = 2.03 Å give 10Dq = 14,510 cm(-1), which is 10% smaller than the experimental figure for MgO:Cr(3+). Nevertheless, when the internal electric field, ER(r), due to the rest of the lattice ions is also taken into account, the calculated 10Dq = 16,210 cm(-1) coincides with the experimental value. Accordingly, the colour shift for different oxides doped with Cr(3+) can be well understood on the basis of this extrinsic contribution to 10Dq usually ignored in a ligand field description. The calculated electrostatic potential, VR(r), related to ER(r), is found to be attractive when the electronic density is lying along <110> directions and |r| > 1 Å driven by the first shell of twelve Mg(2+) ions. The action of VR(r) upon the CrO(6)(9-) complex slightly decreases the energy of t2g(xy,xz,yz) orbitals with respect to that for eg(3z(2) - r(2),x(2) - y(2)) orbitals, thus enhancing the 10Dq value by 0.2 eV. However, the addition of VR(r) induces very small changes in the electronic density, a relevant fact that is related to the (2)E(t(2g)(3)) −> (4)A(2)(t(2g)(3)) emission energy being nearly independent of the host lattice along the series of Cr(3+)-doped oxides.
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Affiliation(s)
- J A Aramburu
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Avenida de los Castros s/n, E-39005 Santander, Spain
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Cimpoesu F, Zaharia A, Stamate D, Panait P, Oprea CI, Gîrţu MA, Ferbinteanu M. New insights in the bonding regime and ligand field in Wernerian complexes. A density functional study. Polyhedron 2013. [DOI: 10.1016/j.poly.2012.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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