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Abstract: In this paper, a modified simple solvothermal method is employed to synthesize Mn3O4 nanocrystals using four different solvents: acetone, ethanol, N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). Mn3O4 nanoparticles with a tetragonal hausmannite nano-structure are characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), as well as superconducting quantum interference device magnetometer (SQUID). The Mn3O4 particle size is found to have a strong dependency on the solvent used. A reaction scheme is proposed to understand this dependency, suggesting that the solvent coordinating capability has a critical effect on Mn3O4 particle size. The stronger the coordinating capability of the solvent is, the smaller the Mn3O4 particle size is. In addition, magnetic properties of the nano-structured Mn3O4 are also tested and discussed. [Copyright &y& Elsevier]

Abstract: Two pure light rare earth iron garnets Pr3Fe5O12 and Nd3Fe5O12 single crystals were synthesized under mild hydrothermal conditions and structurally characterized by single crystal and powder X-ray diffraction methods. Both compounds crystallize in cubic space group Ia3̄d with lattice parameters a=12.670(2)Å for Pr3Fe5O12 and a=12.633(2)Å for Nd3Fe5O12, respectively. The synthesis of compounds was studied with regard to phase evolution and morphology development with hydrothermal conditions. We proposed the formation mechanisms and formulated a reasonable explanation for their growth habits. Ferrimagnetic Curie temperatures which have been inferred from thermo-magnetization curves were 580K for Pr3Fe5O12 and 565K for Nd3Fe5O12, and the transitions of long range order were also evidenced by differential scanning calorimetry method. The result of magnetic properties has shown that moments of the large radius Pr3+ and Nd3+ ions are parallelly coupled with net moments of iron ions. [Copyright &y& Elsevier]

Abstract: Hydrothermal synthesis, characterization and magnetic properties of a series of ABO3-perovskites LaFe1−x Cr x O3 (0≤x≤1) are reported. The alkalinity in initial reaction mixtures plays a critical role in controlling the designed stoichiometry of the final compositions. Their magnetic properties are strongly dependent on the compositions and a maximum magnetic moment is found for the sample at x=0.5. Weak ferromagnetic interaction observed for the samples from x=0 to 0.9 arises from the presence of Fe–O–Fe antisymmetric exchange and Fe–O–Cr superexchange interaction. The weak ferromagnetism as well as the linear variation of the lattice parameters implies the possible random distribution of Fe and Cr ions in B sites of the perovskites. The evolution of magnetic ordering transition temperatures has a close relationship with substituent ratios, for the competition of antiferromagnetism and ferromagnetism. The saturated magnetic moment shows a great improvement compared with that for the samples synthesized by solid state method. [Copyright &y& Elsevier]

Abstract: The single crystals of perovskite fluorides (NH4)2NaVF6 and Na3VF6 were synthesized under mild hydrothermal conditions. The structures of the compounds were determined by means of single-crystal and powder X-ray diffraction analyses, respectively. (NH4)2NaVF6 has a cubic elpasolite-type structure and crystallizes in the space group with lattice constant a=8.495(0)Å. Rietveld refinement indicates that Na3VF6 has a monoclinic structure and is in space group P21 /n. The compounds were characterized by scanning electron microscopy, thermogravimetric and differential thermal analysis, and variable temperature magnetic susceptibility. With the temperature decreasing, the magnetic studies of the compounds showed the magnetic ordering was related to the crystallographic features and isolated magnetic units. [Copyright &y& Elsevier]

Abstract: Fe3+–Nb5+ co-doped SnO2 was prepared at 1200°C by a simple chemical co-precipitation method. The Sn1−2 x Fe x Nb x O2 solid solutions kept cassiterite structure in the range of 0

Abstract: The calcium-doped manganates, Pr1− x Ca x MnO3 (x=0.39, 0.46, 0.70, 0.76), were synthesized as cube-shaped crystalline phases under mild hydrothermal conditions for the first time. The crystals could be grown in one step from solutions of metal salts and potassium hydroxide at temperatures ∼240°C, and found to adopt perovskite-like structure (space group Pbnm). Samples were characterized by powder X-ray diffraction, scanning electron microscopy, inductively coupled plasma analysis and variable temperature dc/ac magnetic susceptibility. The studies indicate that formation of the materials is dependent on the alkalinity and composition of the initial reaction mixtures. The magnetic properties show spin-glass-like behavior due to competing ferromagnetic (FM) and antiferromagnetic (AFM) exchange interactions in Pr1− x Ca x MnO3 with , 0.46. [Copyright &y& Elsevier]

Abstract: Employing 3-dimethylamino-1-propylamine as a template, a new three-dimensional (3-D) zincophosphite (C5H16N2)·[Zn3(HPO3)4]·H2O has been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction (XRD), FTIR, elemental analysis, powder XRD, and thermogravimetric analysis (TGA). The compound crystallizes in the triclinic space group , with cell parameters, a=8.9884(2)Å, b=10.326(2)Å, c=11.917(2)Å, α=66.98(3)°, β=89.01(3)°, and γ=78.98(3)°, V=997.2(3)Å3 and Z=2. The connectivity of the ZnO4 tetrahedra and HPO3 pseudo pyramids results in inifinite edge-sharing, ladderlike chains of 4-membered rings, which are further linked by Zn–O–P bonds to form a 3-D structure that with interesting 12-membered ring channels along the [100] and [001] directions. The diprotonated amine molecules sit in the middle of the channels along the [100] direction and interact with the framework via hydrogen bonds. There also exist channels with 8-membered ring window along the [100] and [010] directions. [Copyright &y& Elsevier]

Abstract: Single crystals of gadolinium holmium silicate hydroxyapatite Gd4.33Ho4.33(SiO4)6(OH)2 have been synthesized at 2.0GPa and 1450°C using a piston-cylinder-type high-pressure apparatus. The crystal symmetry by single-crystal X-ray diffraction analysis is hexagonal, space group (No. 176), with a=9.3142(5)Å, c=6.7010(4)Å, . Gadolinium and Ho are disordered over the two large cation positions, A(1) and A(2), and charge balance in this silicate apatite is maintained by cation vacancies in A(1). Two other apatite-structure crystals investigated have and symmetry, and represent either partially ordered Gd–Ho distributions or crystal strain induced during quenching. [Copyright &y& Elsevier]

Abstract: Employing 4,4′-bipyridine as a bridged ligand, a new three-dimensional (3-D) hybrid zinc phosphate [Zn2(HPO4)2(4,4′-bipy)]·3H2O has been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction. This compound crystallizes in the monoclinic space group C2/c, with cell parameters, , , , , and . The connectivity of the ZnO3N and HPO4 tetrahedra results in a 2-D neutral layer that with interesting 4,82 net along the bc plane. Furthermore, the 4,4′-bipyridine molecule links the 4,82 net into a 3-D structure. The water molecules sit in the middle of the channels and interact with the framework via hydrogen bonds. The compound exhibits intense photoluminescence at room temperature. [Copyright &y& Elsevier]

Abstract: A cobalt phosphonate (H3O)6·[Co4(H2O)4(HPMIDA)2(PMIDA)2)]·2H2O, 1, has been synthesized from a mild solvothermal reaction of Co(II) ion with N-(phosphonomethyl)iminodiacetic acid (H4PMIDA). Compound 1 crystallizes in the triclinic space group with cell parameters of , , , , , and . Compound 1 shows a novel tetra-nuclear molecular structure. In the crystal lattice, molecules of 1 hydrogen bond to each other to form two-dimensional (2D) layers, which are further linked together by the co-crystallized H2O molecules and H3O+ counter ions through hydrogen bonding to form the 3D supramolecular network. Thermogravimetric analysis, IR spectrum, magnetic susceptibility and luminescent spectra are given. [Copyright &y& Elsevier]

Abstract: Two perovskite rare-earth manganites RMnO3 (R=Ho, Dy) were synthesized from the hydrothermal redox reactions of KMnO4 and MnCl2 at 250°C and characterized by means of X-ray diffraction, scanning electron microscopy and SQUID. They are orthorhombic, whereas the hexagonal phases, which were competitive strongly with the orthorhombic phases in solid-state reactions, are avoided in the hydrothermal systems. The pure metastable manganites may serve as a model for understanding the magnetisms of Jahn–Teller distortion and charge ordering. This new synthetic approach leaves many rooms for new doped or undoped RMnO3 compounds. [Copyright &y& Elsevier]

Abstract: A new three-dimensional open-framework gallophosphate: [H3N(CH2)2NH3]1/2·[Ga5 (PO4)4(OH)4] has been prepared by hydro(solvo)thermal synthesis in presence of ethylenediamine (en) as structure-directing agent. Its structure was determined by means of single-crystal X-ray diffraction analysis with the following crystal data: monoclinic space group C2/m, a=10.1604(9)Å, b=12.0085(15)Å, c=7.1892(7)Å, β=90.797(6)°, V=877.08(16)Å3, , , . The total numbers of measured reflections and unique reflections were 3508 and 1300, respectively. It is built up from a new secondary building unit (SBU) Ga4P4O20(OH)4, in which Ga atoms exhibit distorted trigonal bipyramidal coordination and P atoms are in tetrahedral coordination. The SBU Ga4P4O20(OH)4 are linked into a layer by bridge oxygen atoms. The GaO4(OH)2 octahedra link the layers into a three-dimentional framework. Diprotonated ethylenediamine was found in the channel of the framework. The material was characterized by IR spectroscopy, 1H NMR spectra, thermogravimetric and differential thermal analyses and elemental analysis. [Copyright &y& Elsevier]

A novel three-dimensional inorganic–organic hybrid compound, Mn(H2O)[HO3PCH2NH(CH2CO2)2] from a hydrothermal reaction of Mn (II) ion with N-(phosphonomethyl)iminodiacetic acid (H4PMIDA) was reported. The compound crystallizes in the monoclinic P21/n with cell dimensions of a=5.215(5) Å, b=14.111(15) Å, c=12.727(12) Å, β=93.646(16)°, V=934.6(16) Å3 and Z=4. In this structure each Mn atom is six-coordinated with the carboxylic groups and phosphonic groups to form layers along the bc plane. These layers are further connected with the organic moieties of H2PMIDA, resulting in a complicated three-dimensional network structure. Thermogravimetric analysis, IR spectrum and magnetic susceptibility of this compound are given. [Copyright &y& Elsevier]

Two novel organically templated zincophosphites, [C6H4(CH2NH3)2]·[Zn3(HPO3)4] and [CH3CH2CH2NH3]2·[Zn3(HPO3)4] have been synthesized under hydrothermal conditions with different template 1,3-Bis(aminomethyl)benzene and propylamine, and characterized by single-crystal X-ray diffraction. [C6H4(CH2NH3)2]·[Zn3(HPO3)4] crystallizes in the monoclinic space group P21/c, with cell parameters, a=9.5467(10) A˚, b=26.405(2) A˚, c=7.9946(8) A˚, and β=99.472(2)°. [CH3CH2CH2NH3]2·[Zn3(HPO3)4] crystallizes in the orthorhombic space group Pccn, with cell parameters, a=9.8162(15) A˚, b=23.284(4) A˚, and c=8.9306(12) A˚. Two compounds consist of vertex linking of ZnO4 tetrahedral and [HPO32−] pseudopyramidal units. They have similar inorganic frameworks with the same compositions. They are both built up from two-dimensional layers with four- and eight-membered rings and one-dimensional chains composed of four-memberd rings, but their layered structures are different due to the influence of corresponding organic template. To our knowledge, [C6H4(CH2NH3)2]·[Zn3(HPO3)4] is the first mention of a zinc phosphite material with an aromatic template. Two compounds were also characterized by IR spectroscopy, thermogravimetric and differential thermal analyses, and proton-decoupled 31P MAS solid-state NMR spectroscopy. [Copyright &y& Elsevier]

Two organically templated zincophosphites, (C6H14N2)·[Zn3(HPO3)4] and (C4H14N2)·[Zn3(HPO3)4] have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction. (C6H14N2)·[Zn3(HPO3)4] crystallizes in the triclinic space group P1¯, with cell parameters, a=9.363(4) A˚, b=10.051(4) A˚, c=10.051(4) A˚, α=85.777(13)°, β=82.091(9)°, and γ=79.783(9)°. (C4H14N2)·[Zn3(HPO3)4] crystallizes in the monoclinic space group P21/c, with cell parameters, a=9.9512(3) A˚, b=10.1508(3) A˚, c=17.8105(5) A˚, and β=95.6510(10)°. Although the two structures are different, they have the same anionic framework compositions of [Zn3(HPO3)4]2−. Their frameworks are built up from strictly alternating ZnO4 tetrahedra and HPO3 pseudo pyramids by sharing vertexes. There exist channels with an eight-membered ring window along the a- and c-axis. Powder X-ray diffraction, IR spectroscopy, 31P MAS solid-state NMR, thermogravimetric and differential thermal analyses were also carried out. [Copyright &y& Elsevier]