The effect of thickness and annealing condition on the microstructure and magnetic properties of Fe/Pt multilayer thin films

[Fe(0.5 nm)/Pt(0.5 nm)]₄₀, [Fe(1 nm)/Pt(1.5 nm)]₂₀ and [Fe(3 nm)/Pt(3 nm)]₁₀ multilayer were prepared by DC magnetron sputtering. By conventional furnace annealing (CA) at 270–600 °C for various time, all of the films still remained the disordered structure with the soft magnetic phase. By rapid thermal annealing (RTA) at 500 °C for various time, we obtained the [Fe(1 nm)/Pt(1.5 nm)]₂₀ and [Fe(3 nm)/Pt(3 nm)]₁₀ films with L1₂ ordered FePt₃ phase which was almost ferromagnetic at room temperature. However, the [Fe(0.5 nm)/Pt(0.5 nm)]₄₀ films was still disordered state even under RTA. Compared with CA, RTA exposed an outstanding effect on accelerating the phase transition when the film thickness is over [Fe(0.5 nm)/Pt(0.5 nm)]₄₀.     

Li2K(IO3)3与Li2NH4(IO3)3的晶体结构

本文用X射线粉末法测定了Li₂K(IO₃)₃与Li₂NH₄(IO₃)₃的晶体结构和原子参数。发现Li₃K(IO₃)₃,Li₂NH₄(IO₃)₃与Li₂Rb(IO₃)₃同晶型,属单斜晶系,空间群为P2₁/α,每个单胞含有四个化合式量。室温的点阵常数分别为α=11.198?,b=11.046?,c=8.254?,β=111.53°,及α=11.327?,b=11.078?,c=8.341?,β=111.87°。讨论了二元化合物的形成与离子半径的关系。 关键词：     

测定核间距的不对称2D NOESY方法2.Cis-Pt(NH3)2(Guo)2Cl2的不对称2D NOESY实验研究

应用不对称2DNOESHY实验方法研究了顺铂配合物Cis-Pt (NH₃)₂(Guo)₂Cl₂的水溶液中的构象,表明鸟苷同铂配合后其糖环构象发生明显的变化。     

反式二氯二L-苯丙氨酸乙酯合铂分子结构和晶体结构

反式二氯二L-苯丙氨酸乙酯合铂[Pt(C₁₁H₁₅NO₂)₂Cl₂]属单斜晶系,空间群为P2₁,α=13.555(6)?,b=6.487(3)?,c=15.588(5)?,β=109.42(3)°,Z=2。该化合物晶体结构由重原子法求解,用块矩阵最小二乘方法修正,R=0.0617,R_w=0.0575。Pt—N 2.065(14)?,2.084(14)?;Pt—Cl 2.285(7)?,2.312(8)?。结构由以N—H……O氢键联结的分子层交错堆积组成。 关键词：     

含新结构单元[Co3(SS)3(PR3)3]的钴化合物的磁性研究

通过含新结构单元钴化合物:Co₃(bdt)₃(PBu₃)₃(Ⅰ),Co₃(tdt)₃(PBu₃)₃(Ⅱ),[Co₃(bdt)₃(PPh₃)₃][CoBr₃(dmf)](Ⅲ)和[Co₃(edt)₃(PEtB)₃]₂[Co₂Cl₄(Et₂SO₂)₂](Ⅳ)(bdt=1,2-S₂C₆H₄^2-,tdt=4-Me-1,2-S₂C₆H₃^2-,edt=SCH₂CH₂S^2-)的磁极矩和¹H NMR等研究表明:它们均具顺磁性,钴原子之间存在着反铁磁偶合作用,同时还讨论了它们的磁学性质和分子结构之间关系。     

碘酸镁晶体的结构与相变

本文用差热分析、高温和室温X射线衍射分析等方法研究了Mg(IO₃)₂·4H₂O的相变过程: Mg(IO₃)₂·4H₂O晶体属单斜晶系,空间群为P2或Pm,每个晶胞含有两个化合式量,点阵常数为a=8.307?,b=6.627?,c=8.541?,β=1.00°45′。我们用X射线粉末法测定了α-Mg(IO₃)₂的晶体结构。α-Mg(IO₃)₂属六角晶系,其空间群是P6₃。在14℃的点阵参数为a=5.4777?,c=5.1282?,c/a=0.9362。每个单胞含一个化合式量,6O^II占据在6(c)等效位置上,21^V占据在2(b)等效位置上,Mg⁺⁺无序地占据着2(a)等效位置的一半。其原子参数为x_c=0.096,y_c=0.344,z_c=0.162,z_b=0,z_a=0.981。从结构来看,它与α-LiIO₃同晶型,所不同的是2(a)位置只有一半被Mg⁺⁺离子占据着,另一半为空位。 关键词：     

以新型分子距边矢量ν估计和预测烷烃核磁共振碳谱(13C NMR)化学位移和(CSS)

系统研究了核磁共振碳谱与化学位移和规律,以及分子拓扑指数在定量[结]构[波]谱关系（QSSR）中的应用.本文基于矢量路径长度矢量p=（P₁, P₂, P₃,…, P_m）与分子中原子相互作用,提出了一种新型分子距边矢量并发现它与烷烃¹³C NMR 化学位移和有良好线性相关性, 回归方程及其统计参数为:
CSS=bν+p₃=Σ^m_j=0b_jν_j+b₁₀p₃=b₀ν+b₁ν₁+b₂ν₂+b₃ν₃+b₄ν₄+b₅ν₅+b₆ν₆+b₇ν₇+b₈ν₈+b₉ν9_ν+b₁₀P₃ =-13.6011+22.2133 ν₁+28.4121 ν₂+25.9416 ν₃+26.6709 ν₄+14.4976 ν₅+5.7240 ν₆-5.3830 ν₇-3.2152 ν₈-15.0213 ν₉-25.7099 ν₁₀+12.2786P₃ (n=63, R=0.9970, EV=99.68%, RMS=3.7348, F=2418.2; 交互校验CV为: R=0.9893, EV=98.83%, RMS=7.1261, F=664.046); 结果良好.     

In2O3晶体电子结构和光吸收机理研究

为了得到准确的In₂O₃晶体电子结构, 本文分别采用GGA, GGA+U, HSE06的方法计算了电子结构, 并进行了G₀W₀修正, 通过比较计算结果, 得到HSE06+G₀W₀方法计算得到的禁带宽带最接近实验结果. 在此基础上使用Hedin的G₀W₀近似方法和Bethe-Salpeter方程计算得到了In₂O₃晶体的光学性质, 计算结果与实验结果吻合很好, 在此基础上通过对准粒子能带结构、光学跃迁矩阵和光学吸收谱的分析, 给出了In₂O₃晶体的光学跃迁机理.     

Magnetic susceptibility of (IPA)2FeCl4, (IBuA)2FeCl4 and (IPA)2CuCi4 (IPA = isopropylammonium ion and IBuA = isobutylammonium ion)

The magnetic susceptibility of (IPA)₂FeCl₄, (IBuA)₂FeCl₄ and (IPA)₂CuCl₄, where IPA = (CH₃)₂CHNH⁺₃ and IBuA = (CH₃)₂CHCH₂NH⁺₃, were measured in the temperature range form 80 K up to a temperature near the melting points of the samples. The results obtained were interpreted in termw of a canted two-dimensional antiferromagnet. The variation of the magnetic susceptibility with the change in the composition was also discussed.     

Effects of cation- or oxide ion-defect on conductivities of apatite-type La–Ge–O system ceramics

A series of apatite-type La–Ge–O ceramics were prepared and their cation-defect at the 4f+6h sites and oxide ion-defect at 2a site were investigated. In La_xGe₆O_12+1.5x ceramics of x=6–12, the higher conductivities were obtained in the region of apatite composition, La_x(GeO₄)₆O_1.5x−12 (x=8–9.33), and the highest conductivity was achieved for La₉(GeO₄)₆O_1.5 (x=9), where the number of cation (La³⁺) occupying the 4f+6h sites is 9 and the number of oxide ion occupying the 2a site is 1.5. The ceramics with cation- and oxide ion-defects were La_9−0.66xSr_x(GeO₄)₆O_1.5 (x=0–1), La_9−1.33xZr_x(GeO₄)₆O_1.5 (x=0–1), La_9−xSr_x(GeO₄)₆O_1.5−0.5x (x=0–3), La_9−xZr_x(GeO₄)₆O_1.5+0.5x (x=0–1), La_x(GeO₄)_3x−21(AsO₄)_27−3xO_1.5 (x=0–3), La_x(GeO₄)_33−3x(AlO₄)_3x−27O_1.5 (x=0–3), La₉(GeO₄)_6−x (AlO₄)_xO_1.5−0.5x (x=0–3), La₉(GeO₄)_6−x(AsO₄)_xO_1.5+0.5x (x=0–1), La_9.33−xSr_x(GeO₄)₆O_2−0.5x (x=0–1.2) and La_x(GeO₄)_4.5(AlO₄)_1.5O_1.5x−12.75 (x=8.8–9.83), which were prepared by the partial substitution of La³⁺and GeO₄⁴⁻of the basic apatite La₉(GeO₄)₆O_1.5 with Sr²⁺ or Zr⁴⁺ and AlO₄⁵⁻ or AsO₄³⁻. Such substitutions lowered the conductivity of La₉(GeO₄)₆O_1.5. These results were discussed by the electrostatic interaction between Sr²⁺, Zr⁴⁺, AlO₄⁵⁻ or AsO₄³⁻ and oxide ion as a conductive species.     

NaZnLa(PO4)2中Ce3+和Tb3+的发光

采用高温固相反应合成了NaZnLa(PO₄)₂中掺杂Ce³⁺、Tb³⁺的荧光体,对其晶体结构、发光行为进行了研究,并尝试对NaZnLa(PO₄)₂:Ce,Tb荧光体进行调制。NaZnLa(PO₄)₂是LaPO₄的同构物,为单斜晶系独居石结构,从XRD谱数据得到NaZnLa(PO₄)₂基质的晶胞参数为a=0.6823nm,b=0.7045nm,c=0.6497nm,β=1039°,v=0.303nm³,其晶胞参数与单斜LaPO₄的晶胞参数相似。在NaZnLa(PO₄)₂:Ce,Tb荧光体中,Ce³⁺对Tb³⁺有良好的敏化作用,掺杂适量的BO₃^3-、Al³⁺、Dy³⁺,可以增强发光亮度。     

Scattering-controlled recombination of Δ2-light-hole indirect excitons and apparently enhanced quantum confined Stark effect in tensilely strained Si1−yCy/Si (0 0 1) quantum wells

Anomalies are found in the near-band-edge luminescence properties of Δ₂-light-hole indirect excitons in Si_1−yC_y-based tensilely strained quantum wells (QWs). The experimental spectra exhibit a clear signature of phonon-assisted transitions on the lower energy side of the “no-phonon” transition, which indicates the relevance of “virtual” indirect valleys and in-plane k-dispersion, as opposed to the theoretical prediction that the zone-centered Δ₂ valleys take over the conduction band edge. Intervalley scattering between [0 0 1]-Δ₂ valleys and in-plane Δ₄ valleys is suggested as the underlying mechanism. On the other hand, the experimental evidence was found for “apparently enhanced” quantum-confined Stark red shifts for Si_1−yC_y-based QWs. However, quantitative estimates are in conflict with the experimental results and predict a blue shift due to exciton weakening which masks the Stark effect as in the case of Δ₄-heavy hole excitons in Si_1−xGe_x-based QWs.     

含手性膦配体3-MBPA的铂(Ⅱ)配合物的2D NMR研究

利用一维和二维NMR技术,对含有手性膦配体的铂配合物trans-[Pt(3-MBPAH)₂Cl₂](1)和trans-(Pt(3-MBPA)(3-MBPAH)Cl)(2)进行¹H和¹³C NMR谱分析,否定了化合物(2)的结构为trans-[Pt(3-MBPA)₂]的可能,归属了所有的¹H和¹³C NMR谱线,并根据磷和铂及磷与磷的偶合常数确定它们是反式构型.     

Synthesis and superconductivity of (Pb0.5Cd0.5)(Sr0.9R0.1)2(R′0.7Ce0.3)2Cu2Oy

New Pb based layered superconducting cuprates (Pb_0.5Cd_0.5)(Sr_0.9R_0.1)₂(R′_0.7Ce_0.3)₂Cu₂O_y with (R,R′) = (Eu,Gd), (Eu,Dy) and (Nd,Gd), have been successfully synthesized. The structure of (Pb,Cd)(Sr,Eu)₂(Gd,Ce)₂Cu₂O_y is determined using XRD data. The X-ray powder diffraction pattern can be indexed by the tetragonal structure with lattice parameters a = 3.8250 Å, C = 29.2235 Å and a space group of I4/mmm. The effects of synthesis conditions on (Pb,Cd)(Sr,Eu)₂(Gd,Ce)₂Cu₂O_y are studied and a T_c(onset) of 26 K is obtained by resistance measurements. It is isostructural to the superconductor (Pb,Cu)(Sr,Eu)₂(Eu,Ce)₂Cu₂O_y.     

Unified Treatment of Systematics for Even-Even Nuclei with A≥70

By the concept of effective boson numbers, systematics of E₂₁+E₄₁+E₆₁+, R=E₂₁+/E₄₁, B(E2, 0₁⁺→2₁⁺) and Q₀ for even-even nuclei with A≥70 are presented. New features of energy spectra are noticed and an intuitive understanding is given.     

Electrodeposited Co-Pt thin films for magnetic hard disks

ew baths for Co-Pt electrodeposition have been developed and developed and ECD thin films (≤0.3μm) have been prepared and characterized structurally (XRD), morphologically (SEM), chemically (EDS) and magnetically (VSM); their improved corrosion, oxidation and wear resistance have been ascertained. Such alloys appear suitable candidates for magnetic storage systems, from all technological viewpoints. The originally formulated baths contain Co-NH₃-citrate complexes and Pt-p salt (Pt(NH₃)₂(NO₂)₂). Co-Pt thin films of fcc structure are deposited obtaining microcrystallites of definite composition. At Pt 30 at% we obtain fcc films with a=0.369 nm, H_C=80 kA m, and high squareness; increasing Co and decreasing Pt content in the bath it is possible to reduce the Pt content of the deposit, obtaining fcc structures containing two types of microcrystals with a = 0.3615 nm and a = 0.369 nm deposited simultaneously. NaH₂PO₂ additions to the bath have a stabilizing influence on the fcc structure of a = 0.3615 nm, Pt 20 at% and H_C as high as 200 kA/m, with hysteresis loops suitable for both longitudinal or perpendicular recording, depending on the thickness. We have prepared 2.5 in. hard disks for magnetic recording with ECD Co-Pt 20 at% with a polished and texturized ACD Ni-P underlayer. Pulse response, 1F & 2F frequency and frequency sweep response behaviour, as well as noise and overwrite characteristics have been measured for both our disks and high-standard sputtered Co-Cr-Ta production disks, showin improved D₅₀ for Co-Pt ECD disks. The signal-to-noise ratio could be improved by pulse electrodeposition and etching post-treatments.     

K5Bi0.9Er0.1(MoO4)4的晶体生长和光学性质

在化学计量的熔料里,用提拉法生长了K₅Bi_0.9Er_0.1(MoO₄)₄单晶。该晶体属于三方晶系,空间群为R3m,z=1.5,晶胞参数为a=6.029?,c=20.823?(六方表示)。晶体具有层状结构,沿着(0001)面容易解理。晶体在室温下的吸收光谱包括有若干条吸收带,它们是稀土离子所特有的。其中三个主要的吸收峰分别相当于从Er³⁺离子的基态 ⁴I_15/2向 ⁴G_11/2, ²H_11/2和 ⁴I_13/2能级的跃迁。本文还给出晶体中相当于 ⁴I_13/2→ ⁴I_15/2跃迁的荧光发射光谱。 关键词：     

水溶液中N-烷基亚胺二乙酸二氨铂(Ⅱ)配合物的13C NMR研究

在不同pH条件下以N-烷基亚胺二乙酸[R-N (CH₂COOH)₂,R=Me,i-Pr,n-Pr,HO-Et]为配体合成了一系列二氨铂(Ⅱ)类配合物.¹³C NMR (20MHz)研究结果表明该类配体均以N、O与铂配位,配位方式不随合成时pH值的改变而改变,在弱酸条件下,配合物处于交换平衡状态,平衡常数由不同pH下未配位羧基碳的化学位移计算而得.     

Ba10(PO4)4(SiO4)2∶Eu2+荧光体的光谱特性

采用高温固相法合成了荧光体Ba₁₀（PO₄）₄（SiO₄）₂：Ce³⁺和Ba₁₀（PO₄）₄（SiO₄）₂：Eu²⁺,研究了两种荧光体的光谱特性。结果表明,两者都呈现较强的宽带激发特征。根据同种基质中Eu²⁺和Ce³⁺两种离子光谱特征的相关性,通过测得的Ba₁₀（PO₄）₂（SiO₄）₂基质中Ce³⁺的光谱数据估算了Ba₁₀（PO₄）₂（SiO₄）₂：Eu²⁺中Eu²⁺的斯托克斯位移（ΔS）和激发能量,估算结果与Ba₁₀（PO₄）₂（SiO₄）₂：Eu²⁺样品的光谱分析结果十分吻合。Ba₁₀（PO₄）₂（SiO₄）₂：Eu²⁺可以同时被紫光和蓝光激发,发出偏白的绿光,可用作白光LED的荧光粉。     

新型红色荧光粉Na2Ca4(PO4)2SiO4:Eu3+,Bi3+的制备及发光特性

用高温固相法合成了用于白光LED的Na2Ca4(1-x-y)(PO4)2SiO4:xEu3+,yBi3+红色荧光粉.研究了助熔剂H3BO3、二次煅烧时间和稀土掺杂量等制备条件对样品发光性质的影响.结果表明,在1 200℃、助熔剂H3BO3加入量为样品质量的3.8%时可得到更有利于发光的α-NCPS基质,而且掺入Eu3+...