纪念穆斯堡尔效应发现40周年

文章论述了穆斯堡尔效应的发现和穆斯堡尔谱学的基本原理，并对穆斯堡尔谱学在材料科学、生物医学、考古学和地质矿物学中的应用进行了讨论     

用穆斯堡尔谱研究锶铁氧体

本文用穆斯堡尔谱研究化学共沉淀法制备的锶铁氧体粉料在烧结过程中的相变,以及粉料的超顺磁性。分析了粉料粒度对相变过程的影响,并测定了锶铁氧体SrFe₁₂O₁₉的五种晶位的穆斯堡尔谱参数。 关键词：     

穆斯堡尔谱学的近期前景

本文讨论了穆斯堡尔谱学应用的突出特点、显著特征、发展趋势、最新进展以及我国穆斯堡尔谱学界的基本情况。     

穆斯堡尔谱学的近期前景

本文讨论了穆斯堡尔谱学应用的突出特点、显著特征、发展趋势、最新进展以及我国穆斯堡尔谱学界的基本情况。     

实地结构研究中的穆斯堡尔谱学

穆斯堡尔谱学由于具有很高的能量分辨本领而成为固体物质微观结构研究的有力手段。近年来,由穆斯堡尔谱学能得到实地(in situ)结构信息的长处正越来越受到重视。本文在简要回顾穆斯堡尔谱学的原理和穆斯堡尔参数的意义后,评述各种iu situ穆斯堡尔实验方法,最后讨论它在近年来的一些应用实例,着重于表面科学与催化。     

实地结构研究中的穆斯堡尔谱学

穆斯堡尔谱学由于具有很高的能量分辨本领而成为固体物质微观结构研究的有力手段。近年来,由穆斯堡尔谱学能得到实地(in situ)结构信息的长处正越来越受到重视。本文在简要回顾穆斯堡尔谱学的原理和穆斯堡尔参数的意义后,评述各种iu situ穆斯堡尔实验方法,最后讨论它在近年来的一些应用实例,着重于表面科学与催化。     

第六届全国穆斯堡尔谱学会议简讯

第六届全国穆斯堡尔谱学会议简讯第六届全国穆斯堡尔谱学会议于１９９４年１０月２４－２８日在武汉市举行，会议由武汉大学和武汉钢铁公司钢铁研究所联合主办。来自全国高等院校、科研单位的６０余位穆斯堡尔谱学工作者代表出席了本届会议。穆斯堡尔谱学是一门新兴边缘学...     

磁性测量讲座 第二讲 研究磁结构的实验方法(Ⅱ)

三、核磁共振(NMR)和穆斯堡尔 效应(ME)[10-13] 核磁共振和穆斯堡尔效应都属于核技术.它们有共同的物理基础,都是研究物质中原子核处的局部电、磁场对核能级的影响.但是,核磁共振的跃迁发生在由于塞曼效应核基态劈裂而成的次能级之间,而穆斯堡尔效应是在原子核基态与激发态能级     

穆斯堡尔谱法及其应用

文章简介了穆斯堡尔效应、穆斯堡尔谱的产生以及穆斯堡尔效应的应用 ,说明它不仅在理论上具有深刻的意义 ,又有着广泛的应用价值 .     

Bi-YIG的穆斯堡尔谱研究

本文对Y_3-xBi_xFe₅O₁₂石榴石型铁氧体(x=0,0.06,0.15,0.32,0.57,0.85,1.00)的穆斯堡尔谱进行了讨论。对此材料的居里温度随其Bi含量x的增加而升高的机理提出了初步看法。 关键词：     

Features of dynamic crystal field effect in the Mössbauer spectra of human hemoglobins at zero field

Human normal hemoglobin (HbA), partial artificial denatured normal hemoglobins, and several abnormal hemoglobins were investigated by Mossbauer spectroscopy at zero field over a temperature range of 78–180k. The Mossbauer spectra of hemoglobins were approximated to two Lorentzian doublets by the least square method. A distinction of the quadrupole splitting and temperature dependence of quadrupole splitting, assoclated with different conformation of molecules, was detected. Furthermore the features of non—Lorentzian lineshape and temperature dependence of lineshape are discussed in correlation to the dynamic fluctuation of Fe (II) ion.     

Temperature studies of Fe−Mn nodules

Sea nodules were extensively studied over a wide range of temperature ranging from 77K to 1175K using Mossbauer effect and ESR. The Mossbauer studies of the nodules at 77K and room temperature show a quadrupole doublet whereas at higher temperatures magnetic spectra were obtained starting at around 875K which ultimately gives a hyperfine field of around 390 KOe at 1175 K. The Mossbauer spectra recorded at 30K did not show any significant change in the room temperature spectra. The analysis of the spectra upto 775K showed two positions of Fe^R+, vie., octahedral and tetrahedral which were varified by ESR of the diluted samples.     

Fabrication and Mossbauer Study of FeCo Alloy Nanotube Array

Arrays of FeCo nanotubes are fabricated in the pores of porous anodic aluminium oxide templates. Transmission electron microscopic result shows that the nanotubes are regular and uniform. Magnetic hysteresis loops measured at room temperature are different from those of nanowires with the same composition, which are caused by the unique shape of nanotubes. The M6ssbauer spectra show that the hyperfine field is smaller than that of the bulk＇s and increases with decrease of measuring temperature. However, the areas of the doublets appeared in M6ssbauer spectra decrease with decrease of measuring temperature.     

151Eu Mössbauer parameters in rare earth oxides LnEuO3 and EuLnO3, synthesized by high pressure

Abstract

The ¹⁵¹Eu double-rare-earth oxides LnEuO₃, (Ln = light rare-earth elements) and EuLnO₃, (Ln = heavy rare-earth elements) which were synthesized by means of high pressure and high temperature for the first time were investigated using Mossbauer spectroscopy. Considering the asymmetric factor + 0, the ¹⁵¹Eu Mossbauer spectra were fitted by twelve transition lines. Results show that the isomer shifts of ¹⁵¹Eu increase in a linear fashion with increasing one-formula-unit volume v₀ of the oxides because of the lanthanide contraction. The slopes being different for the light and heavy elements.     

Magnetism of iron-containing MCM-41 spheres

Iron species were loaded into the mesopores of MCM-41 spheres by incipient wetness impregnation procedure with Fe(ACAC)₃ as the precursor. The magnetism of the samples was studied by vibrating sample magnetometer (VSM), diffuse reflectance ultraviolet–visible (DRUV-vis) spectra and Mossbauer spectra. The results show that the magnetic behavior of the iron-loaded MCM-41 spheres depends on the content of iron loading, valence, and coordination state of iron ions, testing temperature and the atmosphere for the pyrolysis of the iron precursor.     

Investigation of nonequilibrium phases of Ti−Fe alloys at low content of iron by Mössbauer spectroscopy

An investigaition of the Mossbauer spectra of quenched Ti_1−xFe_x alloys in the region of concentrations 0.0005=x=0.142 has been performed. The analysis of the Mossbauer spectra measured at the 4.2, 78, 100, and 295 K temperatures of the sample allowed the concentration dependence of appearence of the α-, β-, and ω-phases to be established. The dynamical and electronic properties of the revealed phases are discussed.     

Magnetic behaviour and DCEMS study of SnO2 films implanted with 57Fe

Fe implanted SnO₂ films (5 × 10¹⁶ and 1 × 10^{17 57}Fe ions/cm²) characterized by conversion electron Mossbauer spectroscopy (CEMS) are reviewed. The substrate temperatures affect the growth of precipitated iron oxides. The Fe ion implanted film at room temperature (RT) shows no Kerr effect and no magnetic sextet in CEM spectra. The SnO₂ film implanted with ⁵⁷Fe at the substrate temperature of 300 °C show a small Kerr effect although the magnetic sextet is not observed, but post-annealing results in the disappearance of the Kerr effect. This magnetism is considered to be due to defect induced magnetism. Some samples were measured by CEMS at 15 K. SnO₂ (0.1 at %Sb and 3 at %Sb) films, implanted at 500 °C and the post-annealed samples, show RT ferromagnetism due to formation of clusters of magnetite and maghemite, respectively. The layer by layer analysis of these films within 100 nm in thickness has been done by depth sensitive CEMS (DCEMS) using a He + 5 % CH₄ gas counter. The structures and compositions of Fe implanted SnO₂ films, and the effects due to post-annealing were investigated.     

金刚石生长过程中Fe基合金催化机制的研究

 用X光衍射、电子能谱及Mossbauer谱实验方法，测量了高温高压条件下Fe基合金中Fe原子的3d壳层电子状态的变化，揭示了人造金刚石生长过程中，Fe原子3d壳层未成对电子与2P_z电子之间的键合。     

Next nearest neighbor effect in chromite

In this paper the Mossbauer spectra of a chromite at 140K 200K and 298K were measured. Next nearest neighbor effects were used to explain the spectra of the chromite, and multiple doublets of Fe²⁺ ions on the A sites were caused by the different cation combinations on 12 next nearest neighbor B sites. The quandrupole splitting of each of mult iple Fe²⁺ doublets decreases with increasing temperature.     

Electron Spin Resonance study of gamma irradiated MA-AMPS copolymer

Electron Spin Resonance (ESR) spectra of gamma irradiated methylacrylamide-2-acrylamido-2-methyl-propanesulphonic acid (MA-AMPS) are recorded to identify the radical species formed during the irradiation of the copolymer. The ESR spectrum observed for irradiated MA-AMPS copolymer at liquid nitrogen temperature (LNT) (77 r K) is an asymmetric triplet; while the spectrum observed at room temperature (RT) is a quintet. The intensity distribution of both the spectra deviated appreciably from the expected theoretical values. Computer simulations are employed to analyze the ESR spectra observed at different temperatures. The triplet spectrum observed at LNT is simulated to be a superposition of component spectra arising from macroradicals of the type～CH 2 - \dot {\rm C} H-CH 2 ～ (I), radicals of the type \dot {\rm C} H 2 SO 3 H (II), and peroxy radicals (III). In contrast, the RT spectrum is simulated to be a superposition of component spectra arising due to radicals I, II, III together with the component quartet assigned to methyl radicals ( \dot {\rm C} H 3 ). The formation of such free radicals in irradiated copolymer is discussed.