Structural Transition and Magnetic Property of Bi1-xYbxFeO3

Bi1-xYbxFeO3（0〈x〈0.2） powders have been synthesized using a sol-gel method. The X- ray diffraction data show a structural transition from the rhombohedral R3c phase to the orthorhombic Pnma phase between x=0.1 and 0.125, which should induce a ferroelectric- paraelectric transformation. The phase transition is also proven by the Raman spectroscopy. A moderate signal on magnetization appears to illustrate the enhancement of magnetization at the transformation boundary, which is suggested to be the destruction of the spin cycloid structure at low concentration. The appearance of antiferromagnetic ordering is proposed to account for the afterward reduction of the magnetization at high concentration.

Magnetic property and recording performance of chemical deposition CoP thin films

The thickness of CoP thin films prepared by wet chemical deposition is of crucial importance on magnetic property and recording perform-ance. The coercivity of CoP films decreased with increasing film thickness. The coercivity was 45.37 kA m 1 at the thickness of 300 nm, and decreased to 21.65 kA m 1 at 5.7 μm. Recording performance tests indicate that, for drums with the same size, different recorded magnetic pole density have different thickness requirements. For 40 mm diameter magnetic drum, the optimal CoP thickness is 3～10 μm for 256 re-corded magnetic poles, 1～2 μm for 512 recorded magnetic poles, and 500～800 nm for 1024 recorded magnetic poles.

Synthesis,Crystal Structure,Thermal Stability,Luminescence and Magnetic Property of a New Mn^Ⅱ Coordination Polymer

One new coordination polymer, [Mn(Hbtc)(bpy)(HO)]1, was synthesized by the reaction of manganese(Ⅱ) salt under pH-controlled hydrothermal conditions with unsymmetrical polycarboxylic acid of 1,2,4-benzenetricarboxylic acid(Hbtc) and 2,2?-bipyridine(bpy). The structure of complex 1 was characterized by single-crystal X-ray diffraction, IR spectra, powder X-ray analysis, thermal gravimetric analysis(TGA), UV-Vis spectrometry, photoluminescence and magnetic susceptibility. Complex 1 is a one-dimensional(1D) polymeric single-chain structure. Photoluminescence property is quite similar to the bpy ligand. Magnetic susceptibility measurement indicates that 1 shows a weak ferromagnetic coupling between the Mn~Ⅱ ions.

Three-Dimensional Normal Stress for Controlling Electronic Structure and Magnetic Property of Fe2Ge

A system study of the three-dimensional normal stress for regulating electronic structure and magnetic property of Fe_2Ge is studied. The density states of Fe more than 92% contribution come from Fe 3d,the density states of Ge mainly contributed from Ge 4p and Ge 4s,and the Fe 3d spin induces the Ge 4p electron transfer. The inductive effect increases germanium electron energy,weakens the Fe spin density of states,opposes the stability of the ferromagnetic state. The magnetic moment varies from 5 to 3 μB with the stress charges from-30 to 30 GPa. The charge of Fe is negative whereas the Ge atom is positively charged,the Fe atom loses charge,the charge transfers to the Ge atom. The unevenly distributed charge forms the newoccupy state and spin polarization state in the Fe_2Ge electron structure system. The Fe is the electron donor,the total electron is transferred to Ge,but the total numbers of gain electron and total numbers of lost electron are not equal,so the Fe_2Ge electron system may have hybridization between the Fe 3d state and Ge 4p state.The magnetic of Fe_2Ge mainly comes from the unoccupied Fe 3d orbital,the Fe 3d is positive spinpolarization state and the spin-polarization strength is decreased,the Ge 4p is negative spin-polarization state and the spin-polarization strength are increased. M oreover,electrons-spin polarization is relevant to the structure parameters of the Fe_2Ge system,and controls spin-polarized electronic behavior by means of adjusting ferromagnetic.

A One-dimensional Cobalt Coordination Polymer Based on Biphenyl-2,3,3',5'-tetracarboxylic Acid and N-donor Ancillary Ligands: Crystal Structure and Magnetic Property

Hydrothermal reactions of biphenyl-2,3,3A,5A-tetracarboxylic acid（H4bptc） with cobalt salt in the presence of 1,4-bis（2-pyridylmethyl）piperazin（bpmp） afforded one novel coordination polymer, namely, [Co（H2bptc）（bpmp）0.5（H2O）]n（1）. Its structure was established by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra and TG analysis. Complex 1 crystallizes in monoclinic, space group P21/c with a = 11.4839（11）, b = 16.6690（16）, c = 11.5559（11） A, V = 2201.8（4） A3, Mr = 539.35, Dc = 1.627 g/cm^3, μ（MoK α） = 0.841 mm-1, F（000） = 1108, Z = 4, the final R = 0.0309 and w R = 0.0705 for 4090 observed reflections（I 2σ（I））. Complex 1 displays a one-dimensional（1D） chain bridged by bpmp. Two carboxylic groups of H4 bptc ligand adopt μ01-η1：η1 and μ1-η1：η coordination modes to bridge adjacent Co（Ⅱ） ions together with bpmp ligand to give alternately arranged left- and right-handed helical chains. In addition, variable-temperature magnetic susceptibility measurements indicate that complex 1 shows weak antiferromagnetic interactions between the adjacent Co（Ⅱ） ions.

A New Mn(Ⅱ) Coordination Polymer: Synthesis, Structure and Magnetic Property

A new 2D compound,{[Mn6 L3(H2O)8]·0.69(C3 H7 NO)·3.31H2O}n(1,H4 L=1,1’-(1,4-phenylenebis(methylene))bis-(1H-pyrazole-3,5-dicarboxylic acid)),was synthesized and characterized by IR,TGA and X-ray single-crystal/powder diffraction.Compound 1 crystallizes in monoclinic system,space group C2/c with a=26.468(5),b=19.750(4),c=13.660(3)A,β=92.73(3)°,V=7132(2)A^3,Z=4,Mr=1824.12,Dc=1.699 g/cm3,F(000)=3705,R=0.042 and w R=0.117 for 8965 observed reflections(I>2σ(I)).In compound 1,all of the Mn(II)atoms are six-coordinated and take the octahedral geometry of[MnNO5].The 2D compound consists of secondary building unit[Mn3(μ2-O)(R-COO)3](SBU),in which two of the Mn^2+ions exhibit the same coordinated environments while another Mn^2+ion has a different one.The SBUs further connect with each other to form a 1 D inorganic chain which is connected with L^4-ligands to construct a 2D layer.Finally,strong O–H···O hydrogen bonds among the rich carboxyl molecules and O atoms from free DMF and guest water molecules connect the two-dimensional coordination network into a three-dimensional framework.Variable temperature magnetic measurements indicate the antiferromagnetic behavior in the Mn3 core in compound 1.

Rock magnetic property of gravity core CSH1 from the northern Okinawa Trough and the effect of early diagenesis

Detailed rock magnetic investigations were undertaken at 2 -4 cm interval for the gravity core CSHI （with a length of 17.36 m） from the northern Okinawa Trough. Time-scale of the core was constructed by two characteristic tephras and foraminferal assemblages, indicating an age of 50 ka for the bottom of the core. Except for three tephras and abrupt decrease in surface, there are little changes in all kinds of rock magnetic parameters that can be correlated to the climate change for the last 50 ka. Different from the common sediments, most S-ratios （S equals the negative ratio of IRM-0.3T to SIRM, which is an indicator of low coercivity content） of the sediments are smaller than 0. 9, which implies a substantial amount of magnetic minerals with high coercivity. The existence of iron sulphide （ greigite or pyrrhotite） is revealed by representative susceptibility - temperature curves showing 200 350 ℃ Curie temperature in addition to 580 ℃ of magnetite, and also by awful smell during heating and dark heating products. Both the occurrence of authigenic iron sulphide and quick decrease of magnetic parameters near the surface clearly show that sediments from Core CSHI have undergone early diagenesis. The featureless magnetic changes of the whole core except for three tephras mean that the post-depositonal alteration is so strong that most original signals have been destroyed. For the same reason, the organic matter in sediment and sulphate in pore water must have been consumed along with dissolution, precipitation of iron and manganese happening sequencially during the redox reaction series. Great caution must be taken when using these altered chemical parameters for the interpretation of climatic changes.

Hydrothermal Synthesis, Crystal Structure and Magnetic Property of a Novel Mixed Valence Decatungstate: [Cu(2,2′-bipy)_2]_2Na_2W_6~VW4^(VI)O_(30)·2H_2O

A novel Cu（II）-2,2＇-bipy-supported （bipy = bipyridine） mixed valence decatungstate, [Cu（2,2＇-bipy）2]2Na2W6^VW4^VIO30·2H2O 1, has been synthesized and structurally characterized by X-ray analysis. The crystal of 1 is of triclinic, space group P1^- with a= 10.9393（10）, b = 12.0492（2）, c = 12.3783（2）A, a = 80.631（10）, β= 70.226（10）, γ= 72.329（9）^o, V = 1459.64（4）A^3, Z = 1, Dc = 3.582 g/cm^3, F（000） = 1404, R = 0.0553 and wR = 0.1242 for 4607 observed reflections （I 〉 2σ（I））. The EPR spectrum of 1 indicates that its unpaired electrons are placed in the dx2-y2 orbital of the ground state of Cun. Furthermore, compound 1 shows an antiferromagnetic interaction.

Crystal Structure and Magnetic Property of a Two-dimensional Manganese Compound [Mn(PhCOO)_2(4,4'-bipyridine)]_n

A new two-dimensional polymeric manganese compound [Mn（PhCOO）2（4,4＇-bipyridine）]n 1 has been prepared and structurally characterized by X-ray diffraction. The complex crystallizes in space group Pbcn with a = 18.7158（2）, b = 11.6919（3）, c = 9.4799（2）A, V = 2074.42（7）A^3, Z = 4, Mr = 453.34, Dc = 1.452 g/cm^3, μ = 0.670 mm^-1 and F（000） = 932. The final refinement gave R = 0.0458 and wR = 0.1439 for 1358 observed reflections with Ⅰ〉 2σ（Ⅰ）. The complex consists of repeating units of Mn（PhCOO）2（4,4＇-bipyridine）. Each Mn center is sixcoordinated by four carboxylate O atoms of four benzoate anions and two pyridyl N atoms from bipy ligands to furnish a slightly distorted octahedral geometry. The two adjacent Mn atoms are connected by a pair of μ1,3-carboxylate groups to form infinite chains, which are further interlinked by bipy to complete a 2D grid network. The magnetic property of the polymeric complex has also been investigated.

Synthesis,Crystal Structure,and Magnetic Property of One 3D Nickel Coordination Polymer Based on 2-Hydroxy-5-(3',5'-terephthalic acid)Pyridine and 1,4-Bis(1-imdazoly)benzene

One novel nickel coordination polymer, {[Ni（OTP）（bib）1.5（H2O）]·2H2O}n（1, H2 OTP = 2-hydroxy-5-（3＇,5＇-terephthalic acid） pyridine, bib = 1,4-bis（1-imdazoly）benzene）, has been synthesized and characterized by elemental analysis（EA）, IR, powder X-ray diffraction（PXRD）, and thermogravimetric（TG） analyses. The crystal of 1 crystallizes in monoclinic, space group P21/n with a = 12.2860（5）, b = 13.8246（6）, c = 19.0140（8） A, β = 104.3870（1）°, V = 3128.2（2） A3, Z = 4, C32H28N7 Ni O8, Mr = 697.32, Dc = 1.481 g/cm^3, F（000） = 1444 and μ（Mo Kα） = 0.684 mm-1. The final R = 0.0704 and w R = 0.1764 for 5485 observed reflections with I 2σ（I） and R = 0.1087 and wR = 0.2010 for all data. Topology analysis reveals that complex 1 is a 3D 2-fold interpenetrated {4^4·6^6}-nov net based on the 1D [Ni（OTP）]n chain and the 2D [Ni2（bib）3]n sql sheet. And the variable-temperature magnetic susceptibility measurements exhibit weak antiferromagnetic coupling interaction.

Morphology, Size-controlled Synthesis of CoO Nanostructure and Its Magnetic Property

CoO nanostructures with tunable morphology and size have been prepared via a simple one-pot solvothermal synthesis. The as-prepared nanoparticles were fully characterized using X-ray diffraction（XRD）, transmission electron microscopy（TEM）, field-emission scanning electron microscope（FESEM）, etc. The morphology and size of the product can be easily controlled by adjusting the raw materials added. Reaction time and the solvent ratio also play important roles in the synthesis of octahedral nanostructures. The magnetic property of the as-prepared samples was also investigated.

A Carboxylate-bridged Co(Ⅱ) Layer Complex： Synthesis, Structure and Magnetic Property

A 2D coordination polymer, [Co（NPA）（H_2 O）_2]_n（1, H_2 NPA = 3-nitrophthalic acid）, has been synthesized by solvothermal method and characterized by single-crystal X-ray diffraction analysis, FT-IR spectroscopy, elemental analysis, thermogravimetric analysis and powder X-ray diffraction. Complex 1 crystallizes in orthorhombic space group Pbca with a = 7.2261（2）, b = 14.6450（5）, c = 19.6671（7） ？, V = 2081.31（11） ？~3, Z = 8, C_8 H_7 CoNO_8, M_r = 304.08, D_c = 1.941 mg/m^3, μ = 1.686 mm^（-1）, S = 1.054, F（000） = 1224, the final R = 0.0248 and wR = 0.0603 for 1834 observed reflections（I 〉 2σ（I））. The crystal structural analysis demonstrates that the Co（Ⅱ） ions in 1 are linked by single and double μ_2-1,3-bridging carboxylate bridges, forming a 2D layer structure. Moreover, magnetic property of 1 was also discussed.

A New Copper Coordination Polymer with Magnetic Property Based on 3-(1,2,4-Triazol-1-yl)benzoic Acid

A copper coordination polymer, namely [CuL2（H2O）2]·H2O 1（HL = 3-（1,2,4-triazol-1-yl）benzoic acid） has been synthesized by the hydrothermal reaction under 140 ℃. The structure of 1 was characterized by single-crystal X-ray diffraction analysis, elemental analyses, powder X-ray diffraction, IR spectroscopy, and thermogravimetric analysis. Single-crystal X-ray diffraction analysis reveals that 1 crystallizes in P21/n space group with a = 12.374（5）, b = 12.730（5）, c = 12.561（5） A°, β = 91.105（9）o, V = 1978.2（14）A°^3, Z = 4, Dc = 1.618 g/cm^3, μ = 1.160 mm^-1, F（000） = 964, the final R = 0.0449 and w R = 0.1443 with I 〉 2σ（I）. Magnetic measurements show that 1 exhibits antiferromagnetic interactions by the analysis of magnetic test data.

Synthesis,Crystal Structure and Magnetic Property of Ternary Neodymium Zirconium Sulfide,Nd2ZrS5

A new ternary neodymium zirconium sulfide Nd_2ZrS_5 was synthesized by high-temperature solid-state reaction and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic space group Pnma（No. 62） belonging to the Y_2HfS_5 structure-type with a = 11.461（4）, b = 8.009（3）, c = 7.315（3） A, Z = 2 and V = 671.5（4）A3. Its structure features NdS_8 and ZrS_7 polyhedra-constructed a 3-D network. The data of magnetic susceptibility indicate its antiferromagnetic-like behavior without magnetic order down to 2 K.

SYNTHESIS, MAGNETIC PROPERTY AND X-RAY CRYSTAL STUCTURE OF MIXED VALENT COBALT COMPLEX SALT [Co~Ⅲ Cl_2(py)_4][Co~Ⅱ Cl_3(py)]

Complex salt Co_2Cl_5(py)_5 (py=pyridine) was obtained by the reaction of CoCl_2·6H_2O with Bu_4NMnO_4 in pyridine in the presence of benzoic acid. It is monoclinic and crystallizes in space group P2_1/n, fw=690.64, a=28.652(5), b=14.108(4), c=7.424(3) ;β=90.09(1); V=3001(2)~3; Z=4, Dc=1.53g/cm^3. Final R factor is 0.041. The structure consists of a discrete cation [Co~ⅢCl_2(py)_4]^+ and an anion [Co~Ⅱ Cl_3(py)]^-. The Co~Ⅲ ion is coordinated by two Cl^- and four pyridine nitrogen atoms to form an octahedral geometry, and Co~Ⅱ is coordinated by three Cl^- and one pyridine nitrogen atom to form the apices of a tetrahedron. The variable-temperature magnetic susceptility measurement shows no magnet-exchange interaction between Co~Ⅲ and Co~Ⅱ ions.

Photochemical Synthesis and Magnetic Property Investigation of a Mixed-valence 11-Tungstophosphate

A mixed valence lacunary tungstophosphate with Keggin structure was photochemically synthesized. It was proved to be an one electron reduced heteropoly 'blue' by W(V) analysis. The subsequent changes were observed in the UV Vis, IR and 31 P NMR spectra of the mixed valence species due to the introduced 'blue' electron. The magnetic property investigated by means of the Evans method suggested that the 'blue' electron was fully delocalized over the framework of the mixed valence lacunary tungstophosphate, and the vacancy in the lacunary species did not transmit the circulating electron, which thus blocked 'ring current' in some intersecting loops.

AgCu(IO3)3：Synthesis,Crystal Structure and Magnetic Property

A new mixed metal iodate, namely Ag Cu（IO3）3, has been prepared using hydrothermal method. Ag Cu（IO3）3 crystallizes in the triclinic group P1 with a = 7.3063（6）, b = 7.8050（6）, c = 8.2447（6） A, α = 67.212（7）, β = 74.978（7）, γ = 80.972（7）°, V = 417.80（6） A^3 and Z = 2. The structure features one-dimensional [Cu（IO3）3]n^n- anionic chains that are separated by Ag~＋ cations. Such [Cu（IO3）3]n^n- chain is composed of [Cu2O（11）]n chain decorated by unidentate hanging and bidentate bridging iodate groups. Thermal study implies that Ag Cu（IO3）3 is thermally stable up to 460 oC and the optical measurement determined the optical band gap of 3.11 eV with a broad absorption band centered at 765 nm. Magnetic investigations show that Ag Cu（IO3）3 is a soft ferromagnet.

Magnetic Property of a Three-dimensional Copper Metal-organic Framework

A copper metal-organic framework（MOF） compound based on 2,5-thiophenedicarboxylic acid（H2 TDC） ligand, namely Cu（TDC）（H2 O）？DMA（1, DMA = N,N？-dimethylacetamide）, has been synthesized in gram-scale via a one-pot solvothermal route in a high yield of 81.3%. Single-crystal X-ray analysis reveals that the structure of 1 features a three-dimensional（3D） open framework constructed by TDC interconnecting 1D chains of [-Cu（COO）（H2 O）Cu-]n. Thermal property was investigated by TG-MS. The magnetic measurements indicate the existence of weak antiferromagnetic interactions between the Cu2＋ centers in 1.

Direct hydrothermal synthesis and magnetic property of titanate nanotubes doped magnetic metal ions

Pure titanate nanotubes and titanate nanotubes doped with Fe^3＋/Ni^2＋/Mn^2＋ ions were synthesized by the hydrothermal method. In this process,titanate nanotubes were first prepared synchronously with doping Fe^3＋/Ni^2＋/Mn^2＋ ions. The morphology,structure,thermal stability and magnetic property of titanate nanotubes were characterized by X-ray diffraction （XRD）,transmission electron microscope （TEM）,and magnetic measurement. The titanate nanotubes transformed into the anatase titania nanocrystals,and further the mixture of anatase and rutile titania along with increasing temperature. The results indicate that the titanate nanotubes doped with Fe^3＋/Ni^2＋/Mn^2＋ ions are paramagnetic behaviors.