Influence of magnetic ordering on the resistivity anisotropy of α-MnS single crystal

2004 ◽  
Vol 129 (3) ◽  
pp. 195-197 ◽  
Author(s):  
S.S. Aplesnin ◽  
G.A. Petrakovskii ◽  
L.I. Ryabinkina ◽  
G.M. Abramova ◽  
N.I. Kiselev ◽  
...  
1970 ◽  
Vol 14 ◽  
pp. 433-440
Author(s):  
W. S. McCain ◽  
D. L. Albright ◽  
W. O. J. Boo

AbstractLattice constants were measured as a function of temperature by single crystal diffracrometry in the temperature range which includes the Néel temperature of VF2(TN= 7°K). The lattice constants of VF2(D4h14=P42m n m) were measured from room temperature down to 4.2°K. In this range rhe tetragonal c-axis contracts 0.58% from 3.2359 Å (RT) to 3.2170 Å (4.2°K). On the other hand, the a-axes show a net expansion of 0.18% from 4.8023 Å (RT) to 4.8110 Å at 4.2°K. The temperature dependence of the lattice constants can be correlated with anisotropy of exchange forces. Vanadium Ions occupy the center and corner positions of the unit cell. Strong magnetic interactions are directed parallel to the c-axis >001< with considerably weaker interactions parallel to the body diagonals >111< The relative strengths of the two exchange integrals are J >001< = 50 J >111<. As a consequence the magnetic ordering is one-dîmensional along the c-axis and the associated distortions arise from the strong magnetic interactions along this axis.


2019 ◽  
Vol 75 (5) ◽  
pp. 562-567 ◽  
Author(s):  
Jiliang Zhang ◽  
Yong-Mook Kang ◽  
Guangcun Shan ◽  
Svilen Bobev

The crystal structure of the gadolinium iron bismuthide Gd6FeBi2 has been characterized by single-crystal X-ray diffraction data and analyzed in detail using first-principles calculations. The structure is isotypic with the Zr6CoAl2 structure, which is a variant of the ZrNiAl structure and its binary prototype Fe2P (Pearson code hP9, Wyckoff sequence g f d a). As such, the structure is best viewed as an array of tricapped trigonal prisms of Gd atoms centered alternately by Fe and Bi. The magnetic-ordering temperature of this compound (ca 350 K) is much higher than that of other rare-earth metal-rich phases with the same or related structures. It is also higher than the ordering temperature of many other Gd-rich ternary phases, where the magnetic exchange is typically governed by Ruderman–Kittel–Kasuya–Yosida (RKKY) interactions. First-principles calculations reveal a larger than expected Gd magnetic moment, with the additional contribution arising from the Gd 5d electrons. The electronic structure analysis suggests strong Gd 5d–Fe 3d hybridization to be the cause of this effect, rather than weak interactions between Gd and Bi. These details are of importance for understanding the magnetic response and explaining the high ordering temperature in this material.


2001 ◽  
Vol 323-324 ◽  
pp. 472-476 ◽  
Author(s):  
P Javorský ◽  
H Sugawara ◽  
D Rafaja ◽  
F Bourdarot ◽  
H Sato

1985 ◽  
Vol 56 ◽  
Author(s):  
J. Kwo ◽  
D. B. McWhan ◽  
M. Hong ◽  
E. M. Gyorgy ◽  
F. J. DiSalvo

AbstractHigh quality single crystal rare earth Gd-Y superlattices with wavelength varying from 8to 42 atomic layers were grown by the recently developed metal molecular beam epitaxy technique. The crystallinity and coherence of the superlattices were examined by X-ray diffraction, and the profiles of composition modulation and strain modulation were determined from a quantitative analysis based on a simple diffusion model for the Gd-Y interfaces. The sharp boundaries achieved in these metallic superlattices are approaching those in semiconductor superlattices. The various in-plane magnetization behavior at low fieldsamong superlattices of different wavelengths suggests the possible presence of new magnetic ordering structures as caused by the artificial modulation.


1999 ◽  
Vol 41 (3) ◽  
pp. 440-444 ◽  
Author(s):  
V. P. D’yakonov ◽  
V. I. Markovich ◽  
V. L. Kovarskii ◽  
A. V. Markovich ◽  
M. Borowiec ◽  
...  

2013 ◽  
Vol 88 (11) ◽  
Author(s):  
Juan Jiang ◽  
C. He ◽  
Y. Zhang ◽  
M. Xu ◽  
Q. Q. Ge ◽  
...  

2013 ◽  
Vol 68 (12) ◽  
pp. 1279-1287 ◽  
Author(s):  
Oliver Niehaus ◽  
Bernard Chevalier ◽  
Paula M. Abdala ◽  
Florian Winter ◽  
Rainer Pöttgen

X-Ray-pure samples of the solid solutions (Ce1-xLax)RuSn were obtained up to x=0.5. Powder diffraction data show the CeRuSn-type superstructure up to x ≈ 0:3 and the CeCoAl-type subcell for higher lanthanum contents. The structure of a single crystal with x=0.5 was refined on the basis of single-crystal X-ray diffractometer data: CeCoAl type, C2=m, a=1160.8(2), b=477.6(1), c=511.6(1) pm, β = 102:97(2)°, wR=0.0510, 444 F2 values, 20 variables. Magnetic investigations were performed for all samples up to a lanthanum content of x=0.4. No cooperative phenomena could be observed, and all samples show Curie-Weiss behavior above a certain temperature. The cerium valence is about 3.32(2) for all samples of the solid solution. Hence, La3+ has to replace Ce3+ as well as Ce4+ in a particular quantity. The electrical resistivity measurements confirm the suppression of the magnetic ordering and the structural transition upon replacement of cerium by lanthanum. 119Sn Mössbauer spectra of samples with x=0.2 and 0.5 are indicative of single tin sites with isomer shifts of δ =1.86(1)mm s-1 for x=0.2 and δ =1.88(1)mm s-1 for x=0.5. Both signals are subject to significant quadrupole splitting, a consequence of the low site symmetry. Results of XANES measurements are perfectly in line with the cerium valences determined by susceptibility measurements and yield a constant value of 3.16(1) for all investigated compounds


2000 ◽  
Vol 115 (11) ◽  
pp. 587-591 ◽  
Author(s):  
Y. Echizen ◽  
K. Umeo ◽  
S. Hamashima ◽  
T. Fujita ◽  
T. Takabatake ◽  
...  

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3289-3292 ◽  
Author(s):  
J. M. BROTO ◽  
B. RAQUET ◽  
H. RAKOTO ◽  
M. N. BAIBICH ◽  
S. LAMBERT ◽  
...  

We studied the electronic conductivity of the quasi-one dimensional Ca3Co2O6 single crystal. The results evidence a VRH conductivity with temperature-induced crossover between 1D (intra-chain) and 3D transport and the opening of a Coulomb gap in the d bands. At low temperatures, an applied magnetic field induces a large negative magneto-resistance (MR) independent from the 3D magnetic ordering. Both spin-dependent hopping and field-induced suppression of the Coulomb gap are discussed.


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