scholarly journals Low-Temperature Behavior of the Specific Heat for an N-Spin Ferromagnetic Material in an External Magnetic Field

Author(s):  
Seung-Yeon Kim

<p>A ferromagnetic material in the absence of an external magnetic field shows the peak of its specific heat in low temperature, called the Schottky anomaly, which is vital in understanding the low-energy structure of a given material. A general formula for the low-temperature behavior of the specific heat of an N-spin ferromagnetic material in an external magnetic field (the generalized Schottky anomaly) is obtained for the first time. Also, as a representative example of ferromagnetic materials in an external magnetic field, the low-temperature behavior of the specific heat for the Ising ferromagnet is studied.</p>

2012 ◽  
Vol 194 ◽  
pp. 40-44 ◽  
Author(s):  
Jan Fikáček ◽  
Jiří Prchal ◽  
Jan Prokleška ◽  
Ivana Císařová ◽  
Vladimír Sechovský

We have synthesized CeRuSn single crystals and performed measurements of electrical resistivity and specific heat. At high temperatures, abrupt transitions were observed at 290 and 225 K in electrical resistivity during cooling. Both transitions are connected with a large temperature hysteresis. Low temperature properties are dominated by an antiferromagnetic transition at 2.9 K, which involves only half of cerium ions, leaving the rest of them non-magnetic. A significant magnetocrystalline anizotropy was revealed by application of external magnetic field.


2000 ◽  
Vol 14 (02n03) ◽  
pp. 224-229 ◽  
Author(s):  
V. MEENAKSHI ◽  
S. V. SUBRAMANYAM

In this work, the influence of disorder on the electrical properties (DC conductivity and Magnetoresistance) of amorphous conducting carbon films, prepared by the pyrolysis of Tetra chloro phthalic anhydride, is reported and discussed. The low temperature electrical properties are analyzed in terms of the various models developed for disordered electronic systems. The results indicate the possibility of a metal - insulator (M-I) transition, both as a function of preparation temperature and an external magnetic field.


1996 ◽  
Vol 46 (S3) ◽  
pp. 1213-1214 ◽  
Author(s):  
T. E. Hargreaves ◽  
J. Akimitsu ◽  
D. F. Brewer ◽  
N. E. Hussey ◽  
H. Noma ◽  
...  

2016 ◽  
Vol 7 ◽  
pp. 990-994 ◽  
Author(s):  
Xiaoyu Li ◽  
Lijuan Sun ◽  
Hu Wang ◽  
Kenan Xie ◽  
Qin Long ◽  
...  

In contrast to the majority of related experiments, which are carried out in organic solvents at high temperatures and pressures, cobalt nanowires were synthesized by chemical reduction in aqueous solution with the assistance of polyvinylpyrrolidone (PVP) as surfactant under moderate conditions for the first time, while an external magnetic field of 40 mT was applied. Uniform linear cobalt nanowires with relatively smooth surfaces and firm structure were obtained and possessed an average diameter of about 100 nm with a coating layer of PVP. By comparison, the external magnetic field and PVP were proven to have a crucial influence on the morphology and the size of the synthesized cobalt nanowires. The prepared cobalt nanowires are crystalline and mainly consist of cobalt as well as a small amount of platinum. Magnetic measurements showed that the resultant cobalt nanowires were ferromagnetic at room temperature. The saturation magnetization (M s) and the coercivity (H c) were 112.00 emu/g and 352.87 Oe, respectively.


Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 713
Author(s):  
Siya Lozanova ◽  
Ivan Kolev ◽  
Avgust Ivanov ◽  
Chavdar Roumenin

A novel in-plane sensitive Hall arrangement consisting of two identical n-Si three-contact (3C) elements and realized in a common technological process, is presented. In the solution, the minimization of the offset and its temperature drift is achieved by cross-coupling of the outer device contacts. This terminals’ connection provides equalizing currents between the two substrates which strongly compensate the inevitable difference in the electrical conditions in the two parts of the arrangement. As a result, the residual offset of both integrated Hall elements at the output Vout(0) and its temperature drift are strongly minimized. The residual offset is about 160 times smaller than the single-configuration one. The obtained output voltage-to-residual offset ratio at sensitivity of SRI ≈ 98 V/AT is very promising, reaching 6 × 103 at temperature T = 40 °C and induction 1 T. As a result, increased metrological accuracy for numerous applications is achieved. For a first time through the novel arrangement a suppression of sensitivity in the presence of external magnetic field could be achieved in order to obtain permanent offset information. This is one of the key results in the Hall device investigation.


2020 ◽  
Vol 93 (6) ◽  
Author(s):  
Mojtaba Servatkhah ◽  
Reza Khordad ◽  
Arezoo Firoozi ◽  
Hamid Reza Rastegar Sedehi ◽  
Ahmad Mohammadi

1978 ◽  
Vol 24 (3) ◽  
pp. 341-344
Author(s):  
N.G. Theophanous ◽  
T. Sauder ◽  
M. Certier ◽  
C. Carabatos

2011 ◽  
Vol 694 ◽  
pp. 538-542
Author(s):  
Wen Ting Zheng ◽  
Li Qin Jiang ◽  
Zhi Gao Huang

The influnence of the amplitude (H0) and frequency of sweeped magnetic field on the exchange bias He and coercivity Hc for ferromagnetic/ antiferromagnetic films has been simulated with Monte Carlo method. In a cycle, the sweeped frequency is inversely proportional to Monte Carlo steps (MCSs). It is observed that, for smaller MCSs, the values of He and the blocking tempreture Tb reduce evidently with increasing MCSs; for larger MCSs, the values of He and Tb decrease gently with increasing MCSs. It is also found the values of He and Tb decrease obviously with increasing values of H0 (HN0). However, on the contrary, the value of Hc increases with increasing values of H0 (HN0). At low temperature and little HN0, the asymmetric loop may appear, which is attributed to the competition between the relaxation time and the period of the external magnetic field. Moreover, the symmetry of the loops influences evidently the values of He and Hc.


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