Mössbauer spectra for 5 nm Fe3O4 particles coated with different surfactants (the polar end groups as -COONa and -SO3Na) were measured and show a significant influence on superparamagnetic relaxation with and without the solvent. Some phenomena were explained by the superparamagnetism and the surfactant hydrophilicity.
Vol.3, No.2
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1992
2
Research article 01 May 1992
杨 燮龙，姜 继森，景 剑锋，夏 元复，胡 征，陈 新树，何 延辉，U. Gonser
keyword：Fe3O4 particles；Superparamagnetism；Solvent；Mössbauer spectroscopy；
Research article 01 May 1992
张 桂林，陈 绍荣，S Ambe，K Maeda，K Suzuki，Y Sasa，E Yagi，H Yabuki，Z W Huang，F Ambe
A sand sample collected at the foot of Flaming Mountain was studied further. On the basis of the change in the relative intensity after heat treatment, one of the sextets observed in its Mössbauer spectrum at liquid nitrogen temperature was ascribed to goethite. This result provides a useful information on the geological history of the region where the mountain is located.
keyword：Mössbauer spectroscopy；Sand of flaming mountain；
Research article 01 May 1992
Zhang Xiufang，Shen Linming，Bao Hongxia，Ding Xiaolan，Wang Rongxin，Liu Yuanyuan，Gao Naifei，Huang Youwen
The Mössbauer spectroscopy and circular dichroism measurements have been used to investigate the effect of some medical treatments on the red blood cells (RBCs) of the patients with HbH disease and β -thalassemia major, respectively. The results indicate that both splenectomy and treatment with myleran are effective to alleviate the symptoms of anemia for some patients, but both of them are different in the effect on the RBCs of the patients. On the basis of the results, a hypothesis on the course of denaturation in hemoglobin of the patients is proposed.
keyword：β -thalassemia major；Mössbauer spectroscopy；Circular dichroism HbH；
Research article 01 May 1992
Li Yang，Cao Guohui，Ma Ruzhang，Cheng Benpei，Kong Jie
The temperature dependent 57Fe Mössbauer and X-ray diffraction measurement on Bi-system 2:2:2:3 phase have been carried out from 77 K to 300 K. It was found that there are two anomalous behaviors of lattice vibrational modes near 125 K and 220 K. This phenomena of lattice softening above Tc is taken as a precursor effect of superconductivity.
keyword：Mössbauer effect；High-Tc superconductor；Lattice softening；X-ray diffraction；
Research article 01 May 1992
Zeng Yiwei，Wu Xiaoshan，Lu Jiangang，Yan Xiaohua
A series of SmTiFe11-xCox compounds where x ranges from zero to five, have been studied by 57Fe Mössbauer spectroscopy, X-ray diffraction and related magnetic measurements. The radom site occupation of Co atom in SmTiFe11-xCox was found when x ≥ 1. The temperature dependence of the magnetic hyperfine field for SmTiFe11 and the Co concentration dependence of the magnetic hyperfine field for the samples, SmTiFe11-xCox are obtained. Also the Debye temperature of SmTiFe11 have been estimated from the experiments.
keyword：Mössbauer spectroscopy；SmTiFe11 compound；Co doping；
Research article 01 May 1992
Ma Xiaoding，Liu Yihua，Mei Liangmo
Multilayered FeSi/Si amorphous films with fixed FeSi layer thickness and different Si layer thicknesses have been studied by conversion electron Mössbauer spectroscopy at room temperature. The results showed that with decreasing the Si layer thickness, the hyperfine field of samples increased and the thickness of interface dead layers arisen from the atomic interdiffusion effect decreased. These are due to the coupling effect between the magnetic layers. When the Si layers are thinner than 0.88 nm, the direction of the magnetization is out of the film plane.
keyword：Multilayered films；Dead layers；Coupling between the magnetic layers；Conversion electron Mössbauer spectroscopy；
Research article 01 May 1992
Qin Guangyong，Li Shi
About 100 crude Chinese mineral drug samples were investigated with Mössbauer spectroscopy, X-ray diffraction analysis and atomic absorption spectroscopy. The classifications, species and components of Chinese mineral drugs are elucidated. The pharmaceutic and curative mechanisms of these mineral drugs are discussed.
keyword：Mössbauer spectroscopy；XRD；Atomic absorption spectroscopy；Chinese ancient mineral drugs；
Research article 01 May 1992
Qin Guangyong，Li Shi，Gao Zhengyao
The Shenqiu meteorite was investigated by Mössbauer spectroscopy at room temperature, atomic absorption, X-ray diffraction and scanning electron microscopy. In order to determine fired conditions of the meteorite which occurred during the meteorite fall, Shenqiu meteorite samples were fired in an oxidizing atmosphere and a reducing atmosphere at temperatures up to 1300 °C, respectively. These samples also were fired at 800, 1000 and 1200 °C respectively for different time (up to 24 h).
keyword：Mössbauer spectroscopy；Fired meteorites；Phase changes；
Research article 01 May 1992
Wang Guihua，Qiao Wenhua，Li Shi，Dai Zhenghua，Luo Helie
The properties of α -Fe2O3 fine particles with and without adsorbed pyridine were studied by Mössbauer spectra. The effective anisotropy constant K were calculated. The K of pyridine- adsorbed α -Fe2O3 particles is smaller than that of pure α -Fe2O3 particles. A probable mechanism of the decreasing effective anisotropy constant K is discussed.
keyword：α -Fe2O3；Mössbauer spectroscopy；Effective anisotropy constant；
Research article 01 May 1992
刘 荣川，颜 其洁，崔 亚，戚 海华，夏 元复，蒋 建中，U Gonser
Solid- solid surface adsorption of Eu2O3 on amorphous Al2O3 have been investigated by Mössbauer spectroscopy, X- ray diffraction analysis and laser Raman spectra (LRS). No X-ray diffraction peak of crystalline Eu2O3 can be found for all samples studied. The LRS show that two peaks at 998 and 1051 cm-1 assigned to two- dimensional surface europium- oxygen species appear at Eu2O3 content of 18.7 wt%. The peak at 1068 cm-1 due to the surface species and another peak at 342 cm-1 due to crystalline Eu2O3 content start to appear for the sample with an Eu2O3 content of 36.5 wt%. The dispersity of Eu2O3 on the surface of amorphous Al2O3 were compared with that of γ - Al2O3, η - Al2O3 and SiO2 gel. The results of these studies indicate that the structure of Eu2O3 dispersed onto the support surface depend on the structure of support and that there is an inductive effect of support on the structure of the Eu2O3.
keyword：Mössbauer spectroscopy；XRD；LRS；Eu2O3；Amorphous Al2O3；Solid-solid surface adsorption；
Research article 01 May 1992
MÖSSBAUER STUDIES OF HEMOGLOBIN AND THE IMMUNE FUNCTION OF RBC OF THE PATIENTS WITH HEPATIC DISEASES
孙 云汉，王 全兴，龙 建秋，龚 国川，刘 荣川，夏 元复，倪 新蕾，陆 轻铀，黄 润生
Red blood cells (RBC) of the patients with cirrhosis and with primary liver cancer were studied by using Mössbauer spectroscopy. The measurements of RBC from normal adults were made as control. Results showed that the subspectrum representing deoxy-Hb either disappeared or diminished, but no other subspectrum was detected in the samples from the patients. In addition, the immune function of RBC of these two types of patients was measured by using immune-adherence haemagglutination (IAHA), which indicated that its immune function was significantly lower than that of normal adults (P<0.01). These experimental results showed that the components of hemoglobin in RBC are correlated with the immune function of RBC.
keyword：Mössbauer spectroscopy；Red blood cell；Cirrhosis；Primary liver cancer；
Research article 01 May 1992
Yang Xielong，Jiang Keyu，Weng Sihao，Hu Bingyuan，Zhang Fugong，Wu Zheng
A Mössbauer polarimeter consists of a gamma ray source (polarizer), transmitter (sample to be analyzed), analyzer and automatic counting system. This equipment was used to observe the Mössbauer Faraday effect in non- stoichiometric Fe3O4. Experimental results demonstrated that electronic hopping above the Verwey temperature between Fe2+-Fe3+ ions on the octahedral sites is a only localized phenomenon and the recoilless fractions of 57Fe nuclei in Fe3-vO4 (v = 0.02) are 0.71 for A sites and 0.62 for B sites, respectively.
keyword：Mössbauer polarimeter；Faraday effect；
Research article 01 May 1992
Weng Sihao，Wang Jie
The transformations of pyrite in coal during the microwave- chemical treatment for desulfurization of coal was studied with Mössbauer spectroscopy of 57Fe. The results for phase analyses show that the selective dielectric heating by microwave energy can give rise to the thermal decomposition of pyrite FeS2 in coal to new phases, pyrrhotite Fe1-xS (0
keyword：Coal；Desulfurization；Microwave irradiation；Acid-washing；Mössbauer spectroscopy；
Research article 01 May 1992
Qiu Zhaoming，Rang Mei，Huang Junjie
Having beautiful colours and fine features, Xiuyan jade is famous in the world. Mineralogically, Xiuyan jade is serpentine jade. XRD, IR and TEM studies indicate that the jade consists mainly of antigorite (m{Mg3(1-1/m)[Si2O5](OH)1+3(1-2/m}) with a minor amount of chrysotile. Two favourite samples (PxA, Px1-1), chosen for research on 57Fe Mossbauer spectra, are only antigorite. Studies indicate that: a. iron ion in antigorite enters the lattice as impurity; b. Fe2+ and Fe3+ substitute for Mg in the coordination octahedron; and c. the colour of jade is related to content of Fe, and Fe2+/Fe3+ ≤ 1 is favourite for colour-forming.
keyword：Xiuyan jade；Antigorite；Mössbauer spectra；
Research article 01 May 1992
Chen Xinshu，Han Zhiquan
Six kinds of typical commercial Fe2O3 were sampled and divided into two groups A and B. according to the magnetic measurement results. The samples of group A are of susceptibility about 10-4 and the specific saturation magnetization σs 0.2-0.3 A.M2/kg, being consistent with the feature of antiferromagnetic α - Fe2O3. While the samples of group B display strong magnetism with susceptibility 10-1-10-2 and σ s 1.7-12 A.M2/kg. Mössbauer spectra of the samples were investigated at room temperature in an external magnetic field. It is suggested there is the γ - Fe2O3 phase in the group B according to the relative intensities of spectra I(2,5)/I(3,4). This was proved by the Mössbauer spectra for the mixed samples A with γ - Fe2O3 at various contents and by measuring the dependence of specific saturation magnetization on temperature for the samples of group B.
keyword：Mössbauer spectroscopy；Fe2O3；Origin of magnetism；
Research article 01 May 1992
Chen Yilong，Xu Binfu，Cheng Jigao，Ge Yingya
Mössbauer absorption spectra in a natural chromite from Shanxi province of China were measured, covering a temperature range from 12 K to 800 K. Each spectrum at low temperature can be fitted to three doublets: the first two are attributed to tetrahedral T-site Fe ions and the third one to octahedral M-site Fe ions. Such assignment was confirmed by the detailed analyses of the temperature dependent centre shift and other parameters. As a main result, our data strongly supported the ordered distribution with Fe2+ in T- site and Fe3+ in M-site for chromite studied. No evidence for electron hopping processes was detected.
keyword：Mössbauer spectroscopy；Chromite；Next nearest neighbour；
Research article 01 May 1992
Zhai Ya，Zhou Huaiying，Hsia Yuanfu，Liu Rongchuan
Nd-(Fe, Co)-B alloys with Dy and Dy-Al additives have been studied by the Mössbauer effect and X-ray diffraction. The results indicate that the alloys consist of a tetragonal phase, a B- rich phase and a Nd- rich phase. The average magnetic moment of Fe atoms in the tetragonal phase has been determined. The variation of remanence due to Dy and Dy- Al additives has been derived from the Mössbauer data and found to agree with the results of magnetic measurements. The site substitutions of Dy and Al in the alloys are also discussed.
keyword：Mössbauer spectroscopy；Permanent magnet；Additives；Magnetic moment；
Research article 01 May 1992
Yu Zhengfang，Zhang Jiangao，Zheng Yufang
Hydrogen decrepitation and desorption of the Nd16Fe76B8 magnet are studied by X- ray diffraction analysis and 57Fe Mössbauer spectroscopy. The results of the as- cast alloy samples treated under various hydrogen gas pressures at various temperatures are reported. A special hydrogenation- dehydrogenation treatment of the Nd- Fe- B cast alloy can produce excellent isotropic magnet powders and the treated sample has passed a hydrogenation- disproportion- recombination process. The effect of the presence of α - Fe in magnet powders is discussed.
keyword：Mössbauer spectroscopy；Nd16Fe76B8 magnet Hydrogen decrepitation；Desorption；
Research article 01 May 1992
A MÖSSBAUER SPECTROSCOPIC STUDY ON THE STRUCTURE OF Fe-M ULTRAFINE PARTICLE CATALYSTS (M=Mn, Zn, Mg)
Li Xianguo，Shen Jianyi，Zhong Bing，Chen Yi，Peng Shaoyi，Wang Qin，Wu Dong
The structure of Fe- M ultrafine particle catalysts was investigated by in situ Mössbauer spectroscopy. Emphasis has particularly been put on the effect of the second metal component. It was found that the incorporation of second metal component hinders the reduction and carburization of iron- containing phase in the presence of H2 and CO, and the degree of hindrance is in the order of Mg>Mn>Zn due to the interaction between iron and the second metal component. Consequently, the formation of light olefinic products is in the order of Fe- Mg>Fe- Mn> Fe- Zn catalysts consistent with the F-T synthesis performance.
keyword：Mössbauer spectroscopy；Fe-M catalysts；Ultrafine particle；
Research article 01 May 1992
Liu Xuewu，Jin Mingzhi，Zhang Weixing，Liu Milan，Su Wenhui
The solid state solutions of europium transition element oxides Eu (Fe0.8M0.2)O3 (M=Sc, Cr, Mn, Co) are synthesized. The X-ray diffraction of the compound shows that all the compounds possess the perovskite structures. Both the 151Eu Mössbauer spectra and the 57Fe Mössbauer spectra are measured. The hyperfine magnetic field and non- axisymmetric electric field gradient are observed in the 151Eu Mössbauer spectrum. The 57Fe Mössbauer spectrum shows that there are four components of hyperfine fields corresponding to four kinds of different neighbours of the Fe ion.
keyword：Mössbauer effect；Magnetic interaction；Eu- Fe- M-O；
