scholarly journals 1,2,4-Triazole Complexes VIII *

1980 ◽  
Vol 35 (1) ◽  
pp. 115-128 ◽  
Author(s):  
D. W. Engelfriet ◽  
W. L. Groeneveld ◽  
H. A. Groenendijk ◽  
J. J. Smit ◽  
G. M. Nap
Keyword(s):  
Heat Capacity ◽  
Magnetic Moments ◽  
Neutron Powder Diffraction ◽  
Exchange Constant ◽  
Susceptibility Data ◽  
Anisotropic Character ◽  
Field Dependent ◽  
Dependent Behaviour ◽  
Ordered State ◽  
Good Agreement

Co(trz)2(NCS)2 has been investigated by means of magnetic susceptibility and magnetization measurements on single crystals in the temperature range from 1.1 - 300 K, heat capacity measure­ments from 1.5 - 90 K, neutron powder diffraction at 1.2 K and ESR measurements on the Co­doped Zn compound at 9 K. The compound appears to have two-dimensional structural and mag­netic properties. A transition to an antiferromagnetically ordered state takes place at Tc = 5.71 (1) K. Susceptibility measurements along the three orthorhombic axes reveal a strongly anisotropic character. The b axis is found to be the preferred axis of antiferromagnetic alignment. The susceptibility data along b and the heat capacity results are in good agreement with the predictions for the quadratic layer, S=½, XY antiferromagnetic, with an intralayer exchange constant j/k= -5.0(1)K. Below Tc the field dependent behaviour of the magnetization and the susceptibility along the a axis exhibits a transition at ~ 1 kOe. Hidden canting is found to be present. The magnetic structure can be described by four sublattices with the magnetic moments lying in the a-b plane along directions that are at an angle of 7° with the b axis.

1,2,4-Triazole Complexes XII * . Magnetic properties of Fe (1, 2, 4-triazole)2 (NCS)2, a quasi two-dimensional S = ½. antiferromagnet with hidden canting.

1980 ◽  
Vol 35 (8) ◽  
pp. 852-864 ◽  
Author(s):  
D. W. Engelfriet ◽  
W. L. Groeneveld ◽  
G. M. Nap
Keyword(s):  
Heat Capacity ◽  
Magnetic Moments ◽  
Exchange Constant ◽  
Direct Transition ◽  
Bonding Parameters ◽  
Susceptibility Data ◽  
Preferred Direction ◽  
Ising Antiferromagnet ◽  
Heat Capacity Measurements ◽  
Overlap Model

AbstractFe(trz)2(NCS)2 has been investigated by means of magnetic susceptibility and magnetization measurements on single crystals at temperatures 1.8-300 K, heat capacity measurements at 1.5-90 K and neutron powder diffraction at 1.2 K. The compound orders antiferromagnetically at Tc = 8.46(2) K. The susceptibilities along the orthorhombic axes are strongly anisotropic, the a axis being the preferred direction. The susceptibility data along a and the heat capacity results are in reasonable agreement with the predictions for the quadratic layer, S = ½. Ising antiferromagnet, with an intralayer exchange constant J/k = - 7.2(2) K. Below Tc the magnetization curve along the a axis reveals a metamagnetic transition at 1.74 kOe. In accordance with the Ising-like properties, a direct transition from the antiferromagnetic to the paramagnetic state is observed along a at 50 kOe. Hidden canting is found to be present. At 1.2 K the compound appears to be monoclinically distorted with α = 88.3° (with respect to Aba2, the space group at 300 K). The magnetic structure consists probably of four sublattices with the magnetic moments lying in the planes z = 0 and z =½ (with respect to the distorted cell in Aba2) along directions that are at an angle of 8° with the a axis. Ligand bonding parameters are discussed in terms of the angular overlap model.

scholarly journals Investigation of the Orbital and magnetic orderings in VF3

2014 ◽  
Vol 70 (a1) ◽  
pp. C1367-C1367
Author(s):  
Gwilherm Nénert ◽  
Patrick Reuvekamp ◽  
Christina Drathen ◽  
Roland Eger ◽  
F Kraus ◽  
...  
Keyword(s):  
Phase Transition ◽  
Heat Capacity ◽  
Structural Investigation ◽  
Magnetic Moments ◽  
Neutron Powder Diffraction ◽  
Antiferromagnetic Order ◽  
Magnetic Frustration ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase

We report on a magnetic and structural investigation of layered antiferromagnetic system vanadium (III) fluoride. VF3 crystallizes in a distorted ReO3 structure (R-3c) with rotated undistorted VF6 octahedra. The V3+ cations are arranged in a triangular lattice with the possibility of exhibiting magnetic frustration. Polycrystalline samples of VF3 were investigated using heat capacity, dielectric, magnetic susceptibility, synchrotron and neutron powder diffraction methods. Combining our results, we report the first evidence for a first order phase transition resulting from the ordering of the t2g orbitals below 105-110 K. This transition reduces the symmetry to C2/c. We further confirm that VF3 undergoes a long-range antiferromagnetic order at ∼19 K in accordance with literature [1]. The antiferromagnetic order results in a magnetic structure with the magnetic moments alternating between a parallel and b parallel alignments in the ab plane.

Multicanonical Molecular Dynamics Simulation Study of the Liquid-Solid and Solid-Solid Transitions in Lennard-Jones Clusters

2011 ◽  
Author(s):  
Toshihiro Kaneko ◽  
Kenji Yasuoka ◽  
Ayori Mitsutake ◽  
Xiao Cheng Zeng
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Transition Temperature ◽  
Peak Position ◽  
Temperature Curve ◽  
Dynamics Simulation ◽  
Lennard Jones ◽  
Dynamics Simulations ◽  
First Time ◽  
Good Agreement

Multicanonical molecular dynamics simulations are applied, for the first time, to study the liquid-solid and solid-solid transitions in Lennard-Jones (LJ) clusters. The transition temperatures are estimated based on the peak position in the heat capacity versus temperature curve. For LJ31, LJ58 and LJ98, our results on the solid-solid transition temperature are in good agreement with previous ones. For LJ309, the predicted liquid-solid transition temperature is also in agreement with previous result.

1,2,4-Triazole Complexes, IV

1978 ◽  
Vol 33 (7) ◽  
pp. 848-854 ◽  
Author(s):  
D. W. Engelfriet ◽  
W. L. Groeneveld
Keyword(s):  
Neutron Powder Diffraction ◽  
Exchange Constant ◽  
Heisenberg Antiferromagnet ◽  
Saturation Field ◽  
Magnetization Measurements ◽  
Intermediate Spin ◽  
Spin Arrangement ◽  
Pulsed Field Magnetization ◽  
Structural And Magnetic Properties ◽  
Heat Capacity Measurements

Magnetic susceptibility measurements on single crystals of Mn(II)(trz)2(NCS)2 in the temperature range 1.8 - 300 K are reported. The compound has two-dimensional structural and magnetic properties. The data from susceptibility measurements are accounted for by considering the material to be a quadratic-layer, S = 5/2 Heisenberg antiferromagnet. From the comparison of the data with predictions from series expansions the intralayer exchange constant was found to be J/k = -0.25 K. A transition to the antiferromagnetic state is observed at TN = 3.29 K with the b axis being the preferred axis. Magnetization measurements at 1.8 K along the b axis reveal a spin-flop transition at 10.8 kOe. The occurence of a second discontinuity in the magnetization curve at 15.6 kOe is explained by assuming that the spin system goes to the spin-flop state via an intermediate spin arrangement, as is suggested by the presence of tilted MnN6 octahedra. From pulsed-field magnetization measurements at 1.17 K, a saturation field Hc = 74 kOe is found which also leads to J / k = -0.25 K. With the aid of neutron powder diffraction at 1.2 K the magnetic space group was determined to be Apb′a 2′! Preliminary results from heat capacity measurements on the corresponding Fe(II), Co(II), Ni(II) and Cu(II) compounds are reported.

The Effect of Partial Substitution of Non-Magnetic Impurity Zn on the Magnetic Moments of Eu1.88Ce0.12Cu1-yZnyO4+α-δ

2021 ◽  
Vol 1028 ◽  
pp. 15-20
Author(s):  
Muhammad Abdan Syakuur ◽  
Yati Maryati ◽  
Togar Saragi ◽  
Risdiana
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Impurity ◽  
Magnetic Moments ◽  
Magnetic Behavior ◽  
Partial Substitution ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Volume Unit

Structure and magnetic properties of electron-doped superconducting cuprates have been investigated in order to study the effect of magnetic impurity to its physical properties. Here, we reported structure and magnetic properties of Eu1.88Ce0.12Cu1-yZnyO4+α-δ (ECCZO) with y = 0 and 0.03. The properties of ECCZO have been studied from X-ray diffraction data and temperature dependence of magnetic susceptibility data, to elucidate the effect of partial substitution of non-magnetic impurity Zn for Cu to its structure, Tc and the value of magnetic moments per unit volume extracted from susceptibility data in normal state. Magnetic-susceptibility measurements were carried out down to 2 K on-field cooling at 5 Oe for Eu1.88Ce0.12Cu1-yZnyO4+a-d with y = 0 and 0.03. For ECCZO sample with y = 0 and d = 0.0669 indicated the change of magnetic behavior from paramagnetic to diamagnetic below 12 K which is addressed to the Tc onset of this samples. Diamagnetic behavior is observed starting from about 12 K. Above 12 K, all samples show paramagnetic behavior with the values of the magnetic moment in every volume unit increased with increasing Zn.

Structure and Magnetism of REPtMg (RE = Pr,Nd, Sm)

2002 ◽  
Vol 57 (5) ◽  
pp. 488-494 ◽  
Author(s):  
Rainer Kraft ◽  
Gunter Kotzyba ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen
Keyword(s):  
Spin Structure ◽  
Three Dimensional ◽  
Point Of View ◽  
Single Crystal Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Complex Spin ◽  
Ferromagnetic Ordering ◽  
Ordered State

New magnesium based intermetallic compounds PrPtMg, NdPtMg and SmPtMg were synthesized from the elements by reaction in sealed tantalum tubes in a high-frequency furnace. The three compounds were investigated by X-ray powder and single crystal diffraction: ZrNiAl type, space group P6̄2m, a = 752.34(8), c = 412.66(4) pm, wR2 = 0.0668, 341 F2 values, 14 variables for PrPtMg, a = 748.80(8), c = 411.52(4) pm, wR2 = 0.0521, 196 F2 values, 14 variables for NdPtMg and a = 743.90(5), c = 409.80(3) pm, wR2 = 0.0489, 248 F2 values, 12 variables for SmPtMg. From a geometrical point of view these structures are composed of two types of platinum centered trigonal prisms, i. e. [Pt1Mg3RE6] and [Pt2Mg6RE3]. These prisms are condensed via common edges and faces. Together the platinum and magnesium atoms build three-dimensional [PtMg] networks in which the rare earth atoms are located in distorted pentagonal channels. Magnetic susceptibility data of PrPtMg show Curie-Weiss behaviour with an experimentalmagnetic moment of 3.59(2) μB and a paramagnetic Curie temperature of 7.5(5) K. Ferromagnetic ordering is detected at TC = 8.0(5) K with a magnetic moment of 1.75(5) μB/Pr at 4.5 K and 5 T. SmPtMg orders ferromagnetically below 52(1) K with a presumably complex spin structure in the ordered state.

scholarly journals Direct observation of the specific heat of Majorana quasiparticles in superfluid3He-B

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yu. M. Bunkov ◽  
R. R. Gazizulin
Keyword(s):  
Heat Capacity ◽  
Low Temperatures ◽  
Condensed Matter ◽  
Direct Proof ◽  
Edge State ◽  
P Wave ◽  
Exponential Dependence ◽  
Majorana Fermions ◽  
Additional Heat ◽  
Good Agreement

AbstractThe existence of Majorana quasiparticles was predicted in the edge state in topological insulators, especially in the p-wave superfluid medium $${^3}$$ 3 He-B. Due to its purity and coherent quantum state, $${^3}$$ 3 He-B is an ideal platform for searching for Majorana fermions in condensed matter systems. In the limit of extremely low temperatures, the density of Bogolyubov quasiparticles and the heat capacity of $${^3}$$ 3 He-B decrease exponentially. In this article, we present the first observation of the deviation of its heat capacity from exponential dependence in the limit of record low cooling. We found an additional heat capacity that more than doubled the heat capacity of bulk $${^3}$$ 3 He-B and changes as T$$^2$$ 2 . The additional heat capacity is in good agreement with the predicted heat capacity of 2D gas of Majorana. This observation is a direct proof of the existence of Majorana quasiparticles in $${^3}$$ 3 He-B.

Equipotential transformation from multipole systems to dipole systems

1987 ◽  
Vol 414 (1847) ◽  
pp. 359-369
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Spherical Harmonic ◽  
Magnetic Moments ◽  
Numerical Comparison ◽  
Magnetic Dipoles ◽  
Planetary Magnetic Fields ◽  
Vector Sum ◽  
Planetary Magnetic Field ◽  
Good Agreement

The paper shows that a planetary magnetic field expressed in the conventional form of a spherical harmonic expanson can be completely represented by the vector sum of fields produced by a set of magnetic dipoles with different magnetic moments, tilted from the planetary spin axis and offset from the planetary centre by different amounts. For convenience, the transformation from multipole systems to dipole systems is restricted to that from multipoles up to octupole to five dipoles. The scalar equipotential transformation analytically results in 24 equations; these can be subsequently solved for the 24 adjustable parameters in dipole systems with the predetermined ‘main dipole’. The numerical comparison of the jovian magnetic field between the jovian O 4 and the five-dipole models reveals a very good agreement with the subtle details. It is obvious that this type of transformation would open up the simplest practical way to simulate planetary magnetic fields with the dipole patterns.

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