Electronic, Crystal Chemistry, and Nonlinear Optical Property Relationships in the Dugganite A3B3CD2O14 Family

Sn2B7O12F with a 2∞[B14O24]6− layer constructed from the unprecedented [B7O16]11− fundamental building block

A new tin borate fluoride Sn₂B₇O₁₂F features a complicated 3D network composed of the unique [B₇O₁₆]¹¹⁻ FBBs and [Sn₄O₁₂F₂]¹⁸⁻ clusters.

Three new phosphates, Cs8Pb4(P2O7)4, CsLi7(P2O7)2 and LiCa(PO3)3: structural comparison, characterization and theoretical calculation

Three new phosphates with a short cutoff edge were obtained, and the structural comparisons were discussed in detail.

Experimental characterization and first principles calculations of linear and nonlinear optical properties of two orthophosphates A3Al2(PO4)3 (A = Rb, K)

We report the experimental characterization and first principles calculation of linear and nonlinear optical properties of two orthophosphates A₃Al₂(PO₄)₃ (A = Rb, K).

Why Some Noncentrosymmetric Borates Do Not Make Good Nonlinear Optical Materials: A Case Study with K3B5O8(OH)2

Synthesis of deep-ultraviolet (DUV) transparent materials, especially those with noncentrosymmetric structures, remains a great challenge in the solid-state chemistry community. A new DUV transparent borate, K₃B₅O₈(OH)₂, was discovered with a short absorption edge below 200 nm. The title compound crystallizes in a noncentrosymmetric, polar space group, Fdd2 (point group mm2), with the following cell parameters: a = 13.736(9) Å, b = 19.317(12) Å, c = 7.606(5) Å. The structure of K₃B₅O₈(OH)₂ features a 3D framework composed of [B₅O₈(OH)₂]^3- basic building units that are linked by contacts with K⁺ cations and O-H···O hydrogen bonds. Second harmonic generation (SHG) measurements were performed, and an SHG efficiency of 0.5 × SiO₂ was observed. Symmetry dictates that the χ₁₄ component of the macroscopic NLO susceptibility is equal to zero in mm2, which prevents the maximal component of the microscopic NLO susceptibility for [B₅O₈(OH)₂]^3- units (χ₁₄) from contributing to the macroscopic NLO susceptibility of the crystal and therefore limits the SHG efficiency. In contrast, large SHG effects can be observed from compounds containing [B₅O₁₀] units that crystallize in point groups with nonzero χ₁₄, such as 222. These findings provide insight into understanding the relationship between crystal structure and SHG efficiency in [B₅O₁₀]-based compounds and discovering other borate-based DUV materials.

New strategy for designing promising mid-infrared nonlinear optical materials: narrowing the band gap for large nonlinear optical efficiencies and reducing the thermal effect for a high laser-induced damage threshold

To circumvent the incompatibility between large nonlinear optical (NLO) efficiencies and high laser-induced damage thresholds (LIDTs) in mid-infrared NLO materials, a new strategy for designing materials with both excellent properties is proposed. This strategy involves narrowing the band gap for large NLO efficiencies and reducing the thermal effect for a high LIDT. To support these proposals, a series of isostructural chalcogenides with various tetrahedral center cations, Na2Ga2MQ6 (M = Ge, Sn; Q = S, Se), were synthesized and studied in detail. Compared with the benchmark AGS, these chalcogenides exhibit significantly narrower band gaps (1.56-1.73 eV, AGS: 2.62 eV) and high NLO efficiencies (1.6-3.9 times that of AGS at 1910 nm), and also outstanding LIDTs of 8.5-13.3 × those of AGS for potential high-power applications, which are contrary to the conventional band gap view but can be attributed to their small thermal expansion anisotropy, surmounting the NLO-LIDT incompatibility. These results shed light on the search for practical IR NLO materials with excellent performance not restricted by NLO-LIDT incompatibility.

Syntheses, Structures, and Properties of Non-Centrosymmetric Quaternary Tellurates Bi MTeO6 ( M = Al, Ga)

Single crystals of two new metal tellurates Bi MTeO₆ ( M = Al, Ga) with a honeycomb layered structure were obtained by the molten flux method and characterized. The Bi MTeO₆ compounds both crystallize into a non-centrosymmetric trigonal space group of P312 (no. 149) with cell parameters of a = 5.0667(8) Å, c = 4.9920(16) Å and a = 5.107(3) Å, c = 4.932(6) Å, respectively. The non-centrosymmetry of BiAlTeO₆ and BiGaTeO₆ originates from the packing order of the octahedra. In these two structures, TeO₆ octahedra and MO₆ octahedra share edges and form a honeycomb open-framework with [Te MO₆]_∞ layers. The layers of [ MTeO₆]_∞ and [BiO₆]_∞ alternate and are connected along the c-axis by corner-sharing oxygen atoms to form the three-dimensional framework. The chiral compound BiGaTeO₆ exhibits a powder second harmonic generation (SHG) response of ∼0.2 times that of potassium dihydrogen phosphate (KDP) and an absorption edge of 355 nm.

K2TeP2O8: a new telluro-phosphate with a pentagonal Te–P–O layer structure

We report a new telluro-phosphate K₂TeP₂O₈ with an analogously pentagonal [TeP₂O₈]²⁻ layer structure.

Na3Ca4(TeO3)(PO4)3: a new noncentrosymmetric tellurite phosphate with fascinating multimember-ring architectures and intriguing nonlinear optical performance

A new functional compound Na₃Ca₄(TeO₃)(PO₄)₃ exhibits a fascinating multimember-ring configuration and intriguing nonlinear optical performance.

Ion-induced structural and optical performance evolution in LBO-like crystals: experimental and theoretical investigation

A new alkali metal borate fluoride Li₃KB₉O₁₅F has been obtained for the first time with a UV cut-off edge below 175 nm.

Syntheses, structures and properties of metal phosphates Pb2Mg(PO4)2, Pb4Zn8(PO4)8 and α-BaZn2(PO4)2

Pb₂Mg(PO₄)₂, Pb₄Zn₈(PO₄)₈ and α-BaZn₂(PO₄)₂ have been synthesized by the standard solid-state reaction and their structures were determined by single crystal X-ray diffraction for the first time. Pb₂Mg(PO₄)₂, Pb₄Zn₈(PO₄)₈ and α-BaZn₂(PO₄)₂ crystallize in the monoclinic crystal system, P2₁/c, C2/c and the trigonal crystal system, P3[combining macron]m1, respectively. The structure of Pb₂Mg(PO₄)₂ possesses a three-dimensional framework consisting of MgO₆ octahedra and PO₄ tetrahedra and the Pb²⁺ cations reside in the [Mg₆P₆O₁₂] tunnels. Pb₄Zn₈(PO₄)₈ and α-BaZn₂(PO₄)₂ are two-dimensional layered structures with [Zn₄P₄O₁₆]_∞ layers for Pb₄Zn₈(PO₄)₈ and [Zn₃P₃O₁₂]_∞ honeycomb double layers for α-BaZn₂(PO₄)₂. And in the structure of Pb₄Zn₈(PO₄)₈, there are four different Zn-P-O layers, which is reported for the first time in zinc phosphates. In addition, thermal property analysis, and UV-Vis-NIR diffuse reflectance and infrared spectroscopy were also performed. First-principles theoretical studies were also conducted to aid the understanding of their band structures and densities of states.

Na2CdGe2Q6(Q = S, Se): two metal-mixed chalcogenides with phase-matching abilities and large second-harmonic generation responses

Two metal-mixed chalcogenides with phase-matching abilities and large SHG responseshave been systematically reported.

Application of the dimensional reduction formalism to Pb9−xBax[Li2(P2O7)2(P4O13)2] (x = 0, 2, 6, 7): a series of phosphates with two types of isolated polyphosphate groups

Dimensional reduction is used to design and synthesise Pb₉[Li₂(P₂O₇)₂(P₄O₁₃)₂] by using Li₂O to dismantle Pb₃P₄O₁₃.