晶体中3d离子的光学性质

章节摘录

版权页：   插图：   The next consideration is about the vibrational modes of the ligands surrounding the SI.If, as above, we restrict to nearest neighbors in a tetrahedral environment we are left with a cage formed by the four anions, spanning 12 degrees of freedom.On the other hand the number of modes rapidly increases if one includes the next-nearest neighbors.Even worse, one should include all the vibrational modes of the host crystal making the problem quite intractable.To keep the state of affairs manageable some approximations are needed.The main point is that the SI are diluted and localized in the host crystal, the case to which we are here interested.Then one can assume a coupling of the electronic states to only one （or few） crystal lattice modes.In fact in this model, commonly adopted in the literature and quoted as cluster model （ 192）, a quasi molecular approximation is made assuming that only the vibrational motion of the impurity and its nearestneighbors （the cluster） can significantly influence the electronic state of interest.In this approximation the symmetrized normal coordinates of the quasi-molecule are taken as coordinates of the system and developed on the basis of the crystal phonon modes.Then it is assumed that there is only one mode （or few modes） whose expansion coefficients are predominate.Usually, different abundances in the phonons density of states of the host crystal may suggest the dominant mode as well as its energy and symmetry.At times, a second mode needs to be taken into consideration for a more precise description of the coupling. Another point to be discussed is related to the electric-dipole selection rules.As the reader has already noticed in the toy model discussed above, the electronic states are made with d functions.This character still remain after the CF splitting has come into play.The problem now is clear that electric-dipole transitions between the electronic multiplet E and T2 are rigorously forbidden.The problem is beyond our toy model and origins from the dN configuration character of the electronic states.However, a deeper analysis shows that the Coulomb interaction in the free ion which weakly couples the 3dN with other configurations at higher energy, thus making the electronic multiplet E and T2 of indefinite parity and allowing for electric-dipole transitions between them. Finally, it should be noted that once vibrational coordinates enter the total Hamiltonian, the complete vibrational component should also form part of it on the same footing as the electronic component.It is usually considered that the vibrational Hamiltonian in the harmonic approximation which is justified by the low temperatures involved in the motivating experiments.

内容概要

作者:(罗马尼亚)阿弗莱、(爱沙尼亚)布莱克

书籍目录

1 recent development in laser crystals with 3d ions 1.1 introduction 1.2 general properties and aspects of tunable solid-state lasers 1.2.1 the prep rational aspect 1.2.2 the spectroscopic aspect 1.2.3 the laser aspect 1.2.4 comparison between lasers based on the 3d-3d and 4f-4f transitions 1.3 transition metal ion lasers--recent developments 1.3.1 overview of progress in transition metal ion lasers 1.3.2 recent progress in the transition metal ion lasers 1.4 summary references 2 exchange charge model of crystal field for 3d ions 2.1 introduction 2.2 ions with 3d1-configuration （ti3+, v4+, cr5+, mn6+） 2.2.1 ti3+ 2.2.2 v4+ 2.2.3 cr5+ 2.2.4 mn6+ .2.3 ions with 3d2-configuration （v3+, cr4+, mn5+） 2.3.1 v3+ 2.3.2 cr4+ 2.3.3 mn5+ 2.4 ions with 3d3-configuration （v2+, cr3+, mn4+, fe5+） 2.4.1 v2+ 2.4.2 cr3+ 2.4.3 mn4+ 2.4.4 isoelectronic cr3+, mn4+ and fe5+ doped in srtio3 2.5 ions with 3d4-configuration （v+, cfi+, mn3+, fe ） 2.6 ions with 3ds-configuration （mn2+, fe3+） 2.7 ions with 3d6-configuration （co3+, fe2+） 2.8 ions with 3dt-configuration （co2+, ni3+） 2.9 ions with 3ds-configuration （ni2+, cu3+） 2.10 ions with 3d9-configuration （cu2+） 2.11 conclusions references 3 snperposition model and its applications 3.1 background 3.2 underlying assumptions and formulation of the superposition model 3.2.1 superposition model assumptions 3.2.2 superposition model formula 3.2.3 distance dependence in superposition model 3.2.4 linkage with the angular overlap model （aom） 3.2.5 quadratic rotational invariants and the superposition model 3.2.6 superposition model in zero-field splittings 3.3 applications of superposition model in selected systems 3.3.1 different ways of using the superposition model 3.3.2 low-lying states of cr3+ at c3 sites in linbo3 3.3.3 spin-hamiltonian parameters for 3d5 ions in oxide crystals 3.3.4 cr3+ at non-cubic sites in mgo 3.3.5 orbit-lattice coupling for cr3+ in ruby 3.4 conclusions references 4 spin-hamiltonian parameters and lattice distortions around 3dn impurities 4.1 introduction 4.2 calculation methods of spin-hamiltonian parameters 4.2.1 perturbation theory method （ptm） 4.2.2 complete diagonalization of energy matrix method （cdm） 4.3 impurity-ligand distances for 3dn impurities in cubic sites of crystals 4.4 low-symmetry distortions of the 3dn impurity centers in crystals 4.5 defect properties related to the defect structures of 3dn impurity centers in crystals 4.5.1 local compressibility and local thermal expansion coefficient 4.5.2 defect model of 3dn impurity center 4.5.3 local phase transition behavior for the 3dn impurity centers in abx3-type perovskites 4.5.4 determination of the substitutional sites for 3dn impurities in crystals references 5 dynamic jahn-teller effect in crystals doped with 3d ions 5.1 introduction 5.2 a brief survey 5.2.13dl, ti3+ and v4+ 5.2.23d2, cr4+ and v3+ 5.2.33d3, v2+ and cr3+ 5.2.43d4, v+, cr2+ and mn3+ 5.2.53d5, fe3+ and mn2+ 5.2.63d6, fe2+ 5.2.73d7, co2+ 5.2.83d8,ni2+ 5.2.93d9, ni+ and cu2+ 5.3 the hamiltonian 5.3.1 the free ion 5.3.2 the crystalline field 5.3.3 the jt interaction 5.3.4 aworked example 5.3.5 real life approximations 5.4 calculation procedures 5.4.1 the lanczos method 5.4.2 lanczos instabilities 5.4.3 the glauber states approach 5.5 some illustrative examples （fe2+, v2+, cr2+） 5.5.1 fe2+ in ii -vi and m-v semiconductors 5.5.2 v2+ 5.5.3 cr2+ in zns and znse 5.6 conclusions acknowledgements a the symmetric displacements of a tetrahedron references 6 first-principles calculations of crystal field effects and absorption spectra for 3d ions in laser crystals 6.1 introduction 6.2 basic foundations of the dvme metho.d 6.3 applications of the dvme method 6.3.1 microscopic analysis of the crystal field effects and "ligand-impurity ion" charge transfer transitions in cs2nayx6 （x=f, c1, br） crystals doped with cr 6.3.2 calculations of optical spectra for 3d ions in crystals 6.3.3 calculations of the xanes spectra 6.4 conclusion acknowledgements references 7 cobalt complexes in znse crystals as new absorbers for non-linear optical devices 7.1 introduction 7.2 crystal growth 7.3 optical investigations 7.4 molecular dynamics geometry optimization 7.4.1 methods of molecular dynamics simulation 7.4.2 results of calculations 7.5 photo-induced simulation of nonlinear absorption kinetics constants 7.6 conclusion references

编辑推荐

《晶体中3d离子的光学性质:光谱和晶场分析(英文)》编辑推荐：The book is devoted to the analysis of spectral, vibronic and magnetic properties of 3d ions in a wide range of crystals, used as active media for solid state lasers and potential candidates for this role.crystal field calculations （including first-principles calculations of energy levels and absorption spectra） and comparison of these results with experimental spectra, janh-teller effect, analysis of vibronic spectra, materials science applications are systematically dealt with.the chapters are relatively independent and can be read separately.

作者简介

《晶体中3d离子的光学性质:光谱和晶场分析(英文)》内容简介：The book is devoted to the analysis of spectral, vibronic and magnetic properties of 3d ions in a wide range of crystals, used as active media for solid state lasers and potential candidates for this role.crystal field calculations （including first-principles calculations of energy levels and absorption spectra） and comparison of these results with experimental spectra, janh-teller effect, analysis of vibronic spectra, materials science applications are systematically dealt with.the chapters are relatively independent and can be read separately. 

The book can be useful for researchers working in the areas of crystal spectroscopy,materials science and its optical applications, post-graduate and under graduate students.

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