Preparation and Magnetism of CuO/A12O3 and CuO/MgO Artificial Superstructured Films

1991 ◽  
Vol 231 ◽  
Author(s):  
Mitsugu Sohma ◽  
Kenji Kawaguchi
Keyword(s):  
Magnetic Susceptibility ◽  
Copper Oxide ◽  
Vapor Deposition ◽  
Neel Temperature ◽  
Deposition Method ◽  
Néel Temperature ◽  
Mono Layer ◽  
Paramagnetic Contribution

AbstractThree kinds of copper oxide (CuO) films, that is, CuO mono-layer films (MLFs), CuO/A12O3 artificial superstructured films (ASFs) and CuO/MgO ASFs were prepared by a reactive vapor deposition method. Magnetic susceptibility of the MLFs is almost constant against temperature and the Neel temperature (TN) is a little lower than that of bulk CuO. There is paramagnetic contribution proportional to the number of the interfaces for both kinds of ASFs. It is considered to be caused by imperfect -Cu-O-Cu- antiferromagnetic superexchange interactions located in the vicinity of interfaces.

scholarly journals Magnetic and Electrical Transport Properties of Vanadium Telluride

1980 ◽  
Vol 35 (7) ◽  
pp. 701-703 ◽  
Author(s):  
C. Prasad ◽  
R. A. Singh
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Magnetic Susceptibility ◽  
Electrical Transport ◽  
Powdered Sample ◽  
Neel Temperature ◽  
Electrical Transport Properties ◽  
Néel Temperature ◽  
Paramagnetic Curie Temperature ◽  
Temperature Range

Measurements of the magnetic susceptibility of a powdered sample of VTe in the temperature range 90 - 700 K, and of the a.c. electrical conductivity (σ), thermoelectric power (θ) and dielectric constant (ε′) of pressed pellets of the compound in the temperature range 300 -1100 K are reported. The compound is found to be antiferromagnetic with Neel temperature 420 ± 5 K. The effective paramagnetic moment and paramagnetic Curie temperature are found to be 1.6 μB and - 250 K, respectively. The dependence of σ, θ and ε′ on temperature shows no anomaly at the Neel temperature and is indicative of the metallic nature of the compound.

Crystal growth and physical properties of an antiferromagnetic molecule: trans-dibromidotetrakis(acetonitrile)chromium(III) tribromide, [CrBr2(NCCH3)4](Br3)

2021 ◽  
Vol 77 (4) ◽  
Author(s):  
Ranuri S. Dissanayaka Mudiyanselage ◽  
Tai Kong ◽  
Weiwei Xie
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Measurements ◽  
Interaction Analysis ◽  
Theoretical Calculations ◽  
Magnetic Feature ◽  
Maximum Temperature ◽  
Neel Temperature ◽  
X Ray Diffraction ◽  
Néel Temperature ◽  
X Ray

The synthesis, crystal structure determination, magnetic properties and bonding interaction analysis of a novel 3d transition-metal complex, [CrBr2(NCCH3)4](Br3), are reported. Single-crystal X-ray diffraction results show that [CrBr2(NCCH3)4](Br3) crystallizes in space group C2/m (No. 12) with a symmetric tribromide anion and the powder X-ray diffraction results show the high purity of the material specimen. X-ray photoelectron studies with a combination of magnetic measurements demonstrate that Cr adopts the 3+ oxidation state. Based on the Curie–Weiss analysis of magnetic susceptibility data, the Néel temperature is found to be around 2.2 K and the effective moment (μeff) of Cr3+ in [CrBr2(NCCH3)4](Br3) is ∼3.8 µB, which agrees with the theoretical value for Cr3+. The direct current magnetic susceptibility of the molecule shows a broad maximum at ∼2.3 K, which is consistent with the theoretical Néel temperature. The maximum temperature, however, shows no clear frequency dependence. Combined with the observed upturn in heat capacity below 2.3 K and the corresponding field dependence, it is speculated that the low-temperature magnetic feature of a broad transition in [CrBr2(NCCH3)4](Br3) could originate from a crossover from high spin to low spin for the split d orbital level low-lying states rather than a short-range ordering solely; this is also supported by the molecular orbital diagram obtained from theoretical calculations.

scholarly journals The Magnetic Susceptibility Bifurcation in the Ni-Doped Sb2Te3 Topological Insulator with Antiferromagnetic Order Accompanied by Weak Ferromagnetic Alignment

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Shiu-Ming Huang ◽  
Pin-Cing Wang ◽  
Hao-Lun Jian ◽  
Mitch M. C. Chou
Keyword(s):  
Magnetic Susceptibility ◽  
Field Cool ◽  
Zero Field Cool ◽  
Weak Ferromagnetism ◽  
Antiferromagnetic Order ◽  
Zero Field ◽  
Neel Temperature ◽  
Néel Temperature ◽  
Magnetic Anisotropy Energy ◽  
Weak Ferromagnetic

AbstractThe magnetic susceptibility reveals a discontinuity at Néel temperature and a hysteresis loop with low coercive field was observed below Néel temperature. The magnetic susceptibility of zero field cool and field cool processes coincide at a temperature above the discontinuity, and they split at temperature blow the discontinuity. The magnetic susceptibility splitting is larger at lower external magnetic fields. No more magnetic susceptibility splitting was observed at a magnetic field above 7000 Oe which is consistent with the magnetic anisotropy energy. Our study supports that these magnetic susceptibility characteristics originate from an antiferromagnetic order accompanied by weak ferromagnetism.

scholarly journals Der Antiferromagnetismus des Ferritins bei Messungen der magnetischen Suszeptibilität im Temperaturbereich von 4,2 bis 300°K

1965 ◽  
Vol 20 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Georg Schoffa
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Structure ◽  
Magnetic Moment ◽  
Exchange Constant ◽  
Antiferromagnetic Exchange ◽  
Neel Temperature ◽  
Néel Temperature ◽  
Temperature Range ◽  
Experimental Values ◽  
Oxygen Atoms

Measurements of magnetic susceptibility in the temperature range 4.2-300°K show that ferritin is antiferromagnetic with a Néel temperature of 20° ± 3°K. The theory of J. S. SMART for antiferromagnetic exchange between iron atoms clustered in groups of two (“isolated clusters”) gives the best agreement between theoretical and experimental values. The antiferromagnetic exchange constant is J/k=- 4.8 (°K). Reduced magnetic moment for µeff =3.85 μB is due to the transfer of two electrons from oxygen atoms to ferric atoms caused on the cation-anion-cation superexchange. Some models of superexchange are discussed. Antiferromagnetism and superexchange are possibly caused on the cubic magnetic structure of iron-oxygen micelles in ferritin.

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