Zhongxiang Zhou

Na3Cd3B(PO4)4: a new noncentrosymmetric borophosphate with zero-dimensional anion units.

A new noncentrosymmetric borophosphate, Na(3)Cd(3)B(PO(4))(4), has been successfully synthesized by conventional solid state reaction for the first time. It crystallizes in the orthorhombic space group Pmc2(1) with unit cell parameters of a = 13.6854(3) Å, b = 5.3346(11) Å, c = 18.2169(4) Å, and Z = 4. Na(3)Cd(3)B(PO(4))(4) features zero-dimensional [B(PO(4))(4)](9-) anion units with Cd(2+) and Na(+)/Cd(2+) cations located around them, in which the BO(4) tetrahedron is surrounded by four PO(4) tetrahedra by sharing the vertexes of O atoms. Second harmonic generation (SHG) measurements show that Na(3)Cd(3)B(PO(4))(4) exhibits a SHG response 1.1 times larger than that of KH(2)PO(4) (KDP) and is phase matchable.

Li4Cs3B7O14: Synthesis, Crystal Structure, and Optical Properties

A new noncentrosymmetric polyborate, Li(4)Cs(3)B(7)-O(14), has been synthesized using the conventional solid state reaction method. It crystallizes in the trigonal space group P3(1)21 (No. 152) with unit cell parameters of a = 6.9313(6) Å, c = 26.799(3) Å, and Z = 3. The new structure contains an infinite three-dimensional matrix that is built from B(7)O(14) building blocks rarely found in anhydrous borate compounds and LiO(n) (n = 4, 5), CsO(n) (n = 9, 10) polyhedra. The optical characterization of the compound indicates that the compound is phase matchable, and the UV cutoff edge is below 190 nm. IR spectroscopy, thermal analysis, and second-harmonic generation were also performed on the reported material.

Synthesis, Structure, and Properties of the Noncentrosymmetric Hydrated Borate Na2B5O8(OH)·2H2O

Single crystal of hydrated sodium borate Na(2)B(5)O(8)(OH).2H(2)O has been grown with sizes up to 5 x 5 x 3 mm(3) under mild hydrothermal conditions at 180 degrees C. The structure is determined by single-crystal X-ray diffraction and further characterized by IR and TG analyses. It crystallizes in the orthorhombic space group Pna2(1), with a = 11.967(2) A, b = 6.5320(13) A, c = 11.126(2) A, Z = 4, R1 = 0.0183, and wR2 = 0.0483. The crystal structure of Na(2)B(5)O(8)(OH).2H(2)O is made up of Na-O polyhedra, and [B(5)O(8)(OH)](2-) polyborate anions. Transmittance spectrum is performed on the Na(2)B(5)O(8)(OH).2H(2)O crystal, which shows an absorption edge less than 190 nm in the UV region. The powder second-harmonic generation intensity measured by the Kurtz-Perry method indicates that Na(2)B(5)O(8)(OH).2H(2)O is about half that of KH(2)PO(4) (KDP).

H2-assisted control growth of Si nanowires

Large-scale desired silicon nanowires without amorphous silicon oxide sheath have been synthesized by thermal chemical vapor deposition using SiH4 gas at 650degreesC in a flow mixture of H-2 and N-2, compared with the short and thick Si nanowires with amorphous SiOx coating obtained in N-2. Scanning electron microscopy (SEM), Energy dispersive X-ray spectrometry (EDX) analysis, and high-resolution transmission electron microscopy (HRTEM) have been employed to characterize the Si nanowires. The effects of H-2 gas on the catalytic particle size and on the formation of Si nanowires are discussed in detail. Photoluminescence (PL) characteristics further demonstrate the large differences between the H-2-assisted grown Si nanowires and the Si nanowires grown in N-2

Na11B21O36X2 (X=Cl, Br): Halogen Sodium Borates with a New Graphene‐Like Borate Double Layer

Borate not graphene: The [B6O12]∞(6-) single borate layer is a graphene-like layer (see figure). The weak Na(+)-Br(Cl)(-) ionic connection between the layers leads to the layer cleavage, and difficulty of the block crystal growth.

Na2Cd7B8O20: a new noncentrosymmetric compound with special [B3O7] units

A new noncentrosymmetric compound, Na2Cd7B8O20, has been synthesized by solid-state reaction for the first time. The crystal structure has been determined from single crystal X-ray diffraction data. The compound crystallizes in the orthorhombic space group Fdd2 with a = 51.5597(7) A, b = 58.6920(8) A and c = 3.381 A. The crystal structure is composed of CdOn (n = 6, 7), Na–CdOn (n = 5, 6) NaOn (n = 4, 6) polyhedra, [B3O7] and [BO3] units. The [B3O7] unit is built up of three [BO3] groups via corner-sharing, rarely found in borate compounds. The IR spectrum, the optical diffuse reflectance spectrum and nonlinear optical properties of Na2Cd7B8O20 are reported.