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ErFe11.35Nb0.65 AND ErFe11.35Nb0.65Ny have been synthesized and neutron-powder-diffraction experiments at room temperature performed. The ErFe11.35Nb0.65Ny nitride, obtained by gas-solid reaction, retains the ThMn12-type structure of its parent compound. The Nb atoms occupy 8i sites and the nitrogen atoms are located at 2b sites. The atomic magnetic moments of the Er ions are antiparallel to those of the Fe atoms. Upon nitrogenation, the lattice cell expands mainly along the a-axis and the atomic magnetic moments of Fe are enhanced. 相似文献
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用中子衍射方法研究了室温下KLiSO_4的晶体结构,进一步确定了Li原子的位置,所得到的结果与近年采用X射线分析的结果在z/c上的差异小于1%。 相似文献
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Larmor Precession and Tunnelling Time of a Non—Relativistic Neutral Spin—1/2 Particle Through an Arbitrary Potential Barrier 下载免费PDF全文
We investigate the Larmor precession of a non-relativistic neutral spin-1/2 particle in a uniform constant magnetic field confined to the region of a one-dimensional arbitrary potential barrier.With the help of a general spin coherent state it is explicitly shown that the spin precession time is equal to the dwell time.For the special case of a symmetric rectangular potential barrier,the precession time is also in agreement with the transmission time.We present a numerical estimation of the precession time showing an apparent superluminal tunnelling. 相似文献
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In this paper neutron diffraction experiments were performed for Fe-substituted Mn12 in order to determine the sites of Fe atoms. The results of structure refinements for the sample with our accessed highest Fe content showed that all Fe atoms occupied Mn(3) sites in the Mn12 skeleton. The x-ray absorption fine structure experiments as well as multiple scattering simulations gave the same result. Thus we concluded that Fe atoms only occupied Mn(3) sites. This conclusion also means that Fe-substituted Mn12 series only includes the four single-molecule magnets of [Mn12-xFexO12(CH3COO)16(H2O)4]·2CH3COOH·4H2O (x = 1, 2, 3, and 4), denoted by Mn11Fe1, Mn10Fe2, MngFe3, and Mn8Fe4, respectively. 相似文献
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We report the discovery that the low-temperature magnetic relaxation in Mn12Ac single crystals strongly depends on the shape of the samples. The relaxation time exhibits a minimum at the phase transition point between ferromagnetic and antiferromagnetie phases. The shape dependence is attributed to the dipolar interaction between molecular magnets. 相似文献
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The crystal structure and magnetic properties of R2Fe17-xCrx(R=Dy,Er,0≤x≤3) compounds have been investigated by me ans of X-ray diffraction and magnetization measurements. These compounds have hexagonal Th2Ni17-type structure. The unit-cell volumes decrease with the increase of Cr concentration x. The Curie temperature Tc of the Er2Fe17-xCrx compounds increases from 320 K for x=0 to 403 K for x=1.0 and then decreases with further increase of x. The Cur ie temperat ure Tc of Dy2Fe17-xCrx compounds increases from 364 K for x=0 to 435 K for x=1.0 and then decreases with further increase of x. The saturation magnetization of these compounds shows an approximately linear decrease with the increase of x. Spin reorientation transitions occur s in Er2Fe17-xCrx(x=2.0 and 3.0). 相似文献
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EFFECT OF MANGANESE SUBSTITUTION IN R2AlFe16-x Mnx(R=Y,Ho,Nd AND Pr)COMPOUNDS ON STRUCTURAL AND MAGNETIC PROPERTIES 下载免费PDF全文
The structural and magnetic properties of R2AlFe16-xMnx(0≤x≤8 for Y,Ho,0≤x≤10 for Pr, 0≤x≤16 for Nd)compounds have been investigated by means of X-ray diffraction and magnetization measurements.The R2AlFe16-xMnx compounds have a hexagonal Th2Ni17-type structure for R=Y and Ho, and a rhombohedral Th2Zn17-type structure for Nd and Pr.With increasing x,the unit-cell volumes have a small increase initially,followed by a greater linear increase.The Curie temperature and the saturation magnetizati on of these compounds show marvelous drop with increasing x.Compensation point was observed in the temperature dependence of the magnetization for Ho2AlFe12Mn4 compound. 相似文献
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