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1.
The magnetic susceptibility of Ni(BrO3)26H2O was measured from 20 K down to 0.07 K. A sharp peak at 0.21 K interpreted as the onset of long range antiferromagnetic order of the tetrahedral type. 相似文献
2.
The differential magnetization of Ni(ClO4)26NH3 and Ni(BF4)26NH3 was measured as a function of temperature (20 to 0.3 K) and magnetic field (up to 40kOe). An antiferromagnetic transition was found at TN = 0.45 K for the Ni(ClO4)26NH3 and TN = 0.43 K for the Ni(BF4)26NH3, and a portion of the magnetic phase diagram was determined. The interpretation of the data in terms of a uniaxial model yielded (D/k) ~ 0.2 K for both salts. 相似文献
3.
报道了Ni(C3H10N2)2NO2(ClO4)晶体在T=1.5K温度和W波段的ESR实验.建立了d8离子基态3A2(F)的零场分裂参量D,E,和g因子与斜方对称晶场势参量间的关系,并应用于Ni(C3H10N2)2NO2(ClO4)晶体.计算值与实验数据符合很好,表明所给关系式是合理的. 相似文献
4.
本文通过对[Fe 3O(Ala) 6(H 2O) 3](ClO 4) 7和[Fe 3O(Gly) 6(H 2O) 3](NO 3) 7·3H 2O的ESR谱的解析及变温磁化率的研究,得出它们的ESR谱具有各向同性的特点;朗德因子分别为2.019和1.997;两种配合物中铁离子间有反铁磁相互作用. 相似文献
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ENDOR measurements at 25 K have been used to determine the hyperfine coupling tensors for all ten protons in the VO(H2O)5 2+ ion in single crystals of Mg(NH4)2(SO4)26H2O. The traceless components of all the tensors are close to axial and their use in a point dipole treatment enables a very plausible geometrical model of the complex ion to be constructed. Six of the protons in the equatorial water molecules have substantial positive isotropic couplings and it is suggested that these reflect the direct admixture of hydrogen 1s components into the singly occupied orbital. 相似文献
7.
A Cl2- centre has been trapped in X or γ-irradiated Ca(ClO3)2. 2H2O single crystals at 298 K, when the irradiated crystals were illuminated with ultra-violet light (360 nm). This centre is formed at the expense of ClO2 centres in this crystal. This Cl2 - centre is trapped at two magnetically inequivalent sites in the crystal lattice and these sites become equivalent when the static magnetic field is parallel or perpendicular to the b axis. At many orientations this centre reveals ‘super-hyperfine’ interaction with a proton (I = 1/2) of the water of crystallization. The magnetic parameters are close to those observed in alkali chlorides and the E.S.R. spectrum has been fitted to an orthorhombic spin hamiltonian. The principal g values are gxx = 2·035, gyy = 2·033 and gzz = 2·000 and those of the A values are Axx = 15·0, Ayy = 31·0 and Azz = 109·0 G. The shfs parameters are A ‖' = 5·0 A ⊥' = 1·0 G. The VK centre trapped in this lattice is exceptionally stable at room temperature. 相似文献
8.
《Journal of Physics and Chemistry of Solids》1987,48(1):29-31
EPR of Mn2+ doped (∼ 1%) in single crystal of zinc fluoroborate hexahydrate has been studied between 94 and 353 K. Angular variation study of the spectra indicated that the crystal field distortion has a trigonal symmetry along the crystallographic c-axis. The D distortion parameter has two linear regions in its thermal variation. It varies above 200 K as D = (149 + 0.107T)G and below 150 K as xzD = (127 + 0.228T)G. A “knee”-like curve links these two linear regions confirming an anomaly observed in a previous work at 181 K due to a phase transition. Other spin Hamiltonian parameters are g = 2.000 ± 0.001, a = (8.9 ± 1.5)G, A = (97.9 ± 0.9)G and B = (97.0 ± 0.9)G. They are constant with temperature. 相似文献
9.
From a temperature dependent ESR study of Mn2+-doped crystals of M(BF4)2·6H2O, M Zn, Co and Ni, new structural phase transitions have been detected and studied. First order structural phase transitions occur in Co(BF4)2·6H2O at T1 ~ 281K, T2~189 K and T3~172K (during cooling), in Zn(BF4)2·6H2O at T1 ~ 286 K and in Ni(BF4)2·6H2O at T1 ~ 301 K. A continuous phase transition occurs in Co(BF4)2·6H2O at Tp ~ 257 K, in Zn(BF4)2·6H2O at Tp ~ 277 K and in Ni(BF4)2·6H2O at Tp ~ 294 K. The ESR spectral characteristics suggest similarities in the structures of these fluoroborate compounds in the phase above T1 with the room temperature structure of Mg(ClO4)2·6H2O. All these compounds are found to have a tendency to crystallise in a triply-twinned pseudo-hexagonal form, although the unit cell above T1 is found to be orthorhombic. The structural changes related to the water octahedron around the metal at T1 were found to be very small and basically the same for these three compounds. Although the unit cell structure of Fe(BF4)2·6H2O above the first order phase transition temperature T1 was found to be similar to that of the other fluoroborate compounds, the structural changes occurring at T1 appeared to be quite different. The low temperature thermal behaviour differs considerably in the Co, Fe and Zn compounds. 相似文献
10.
The gamma-irradiated samples of vacuumed powder and single crystal of C2H2O4.2H2O have been investigated by ESR method. the spectra of these single crystal and unvacuumed powder are attributed to R C HOH radical, but the peaks belonging to this radical in the gamma irradiated powder sample are not observed in the spectrum after having been vacuumed. After a and g tensor values of this radical have been calculated, it was observed to be anisotropic. At low temperature, a considerable change in the spectrum has not been observed. 相似文献
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《International Journal of Mass Spectrometry and Ion Physics》1978,26(2):205-213
The kinematics of the reaction H2O+(H2,H)H3O+ were studied in crossed-beam experiments in the low collision-energy range 0.1–2 eV (c.m.). The scattering diagrams, center-of-mass angular distributions, and product relative translational energy distributions obtained show that the reaction proceeds predominantly by the impulsive, stripping mechanism. The translational exoergicity vs. collision energy plot obeys the spectator-stripping prediction. 相似文献
14.
Magnetic properties of Tm2O3 were studied by means of magnetometry as well as by heat capacity measurements. The specific heat data were collected down to 0.35 K, and yielded some new information about crystal field splitting of the 3H6 thulium multiplet. Some anomalous behaviour of the specific heat below 5 K was observed. It turned out, that this anomaly can be nicely described by Schottky contribution originating from crystal field levels distribution of the Tm3+ multiplet. No magnetic ordering was evidenced down to the lowest temperatures studied. 相似文献
15.
We have measured the heat capacity of superconducting, single phase YBa2Cu3O7 in the temperature range 2 to 18 K. An extrapolation of the data between 4 and 9 K gives aC/T (T → 0) of ∼ 25 mJ/mole K2. The Debye temperature obtained from the high temperature linear portion ofC/T vsT
2 plot is 325 K. 相似文献
16.
The infrared spectrum of potassium ferrocyanide trihydrate has been recorded both in the para and ferroelectric phases. From
a combined study of the IR and Raman spectra, it is concluded that there are two sets of water molecules present in the lattice,
one set being involved in stronger hydrogen bonding than the other. The ferroelectric transition appears to be associated
with an ordering of the water dipoles. 相似文献
17.
Two kinds of time differential Mössbauer spectra of57Co-labelled Co(BrO3)2·6H2O were measured at room temperature by delayed coincidence technique, i.e., one was the delayed coincidence between 122 keV γ ray and 14.4 keV γ ray (γ, γ-ray coincidence), and another was the coincidence between 6.3 keV KX ray and 14.4 keV γ ray (X, γ-ray coincidence). The time dependence of chemical states of57Fe-species were observed on γ, γ-ray and X, γ-ray coincidence Mössbauer spectra. The relative area intensities of57Fe(II) observed on the X, γ-ray coincidence spectra were larger than those on the γ, γ-ray coincidence spectra on every time windows. 相似文献
18.
《Solid State Ionics》2006,177(26-32):2453-2456
A new hydroxonium iron phosphate, (H3O)[Fe(H2O)]3[H8(PO4)6]·3H2O, was synthesized through a precipitation route by means of acidic media. The crystal structure was solved by X-ray powder diffraction. Electrochemical characterizations, performed on this compound, show reversible intercalation of lithium and substantial lithium diffusion. Protonic conductivity is observed in agreement with the simultaneous presence of H2O, hydrated protons and OH groups in the large intersecting tunnels of this intersecting tunnel structure. 相似文献
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L. F. Moreira L. M. A. Diehl E. C. Torres-Tapia P. H. Domingues E. Mattievich 《Hyperfine Interactions》1994,83(1):191-197
Synthetic crystals of phosphoferrite were studied by Mössbauer spectroscopy for temperatures ranging from 4.2 to 17.5 K. The analysis of the behaviour of the hyperfine fields for the two unequivalent sites near the Néel temperature (17.4 K) allowed the determination of the critical exponent for each site as
1=0.171 and
2=0.314. 相似文献