Founder: Northern (Arctic) Federal University named after M.V. Lomonosov

Editorial office address: Russian Federation, 163002, Arkhangelsk, Naberezhnaya Severnoy Dviny 17, office 1410a

Phone: (818-2) 21-61-00(15-33)
e-mail: l.zhgileva@narfu.ru
http://aer.narfu.ru/en/

16+

ABOUT

Experimental Justification of the Theory of Dispersed Medium Spin Paramagnetism. P. 114–120

Версия для печати

Section: Physics. Mathematics. Informatics

UDC

538.955

Authors

Koposov Gennadiy Dmitrievich
Institute of Natural Sciences and Biomedicine, Northern (Arctic) Federal University named after M.V. Lomonosov (Arkhangelsk, Russia)
e-mail: fc.genphys@pomorsu.ru
Sofronov Evgeniy Leonidovich
Institute of Natural Sciences and Biomedicine, Northern (Arctic) Federal University named after M.V. Lomonosov (Arkhangelsk, Russia)
e-mail: e.sofronov@narfu.ru

Abstract

The paper summarizes the results of the experimental studies of diaparamagnetic phase transition in dispersed medium. Research technique is based on the Gouy method for measuring the magnetization and magnetic susceptibility of weakly magnetic materials using the torsion balance and the special chamber for low temperature measurements. The features of the field, humidity and temperature dependences of the magnetic susceptibility and magnetization composing the experimental basis for constructing a theory of this phenomenon are described. The field dependences indicate nonlinearity between the magnetization and magnetizing force and are similar to the ferromagnetics specific dependencies. Very high values of the magnetic susceptibility can’t explain the phenomenon, taking into account only the paramagnetism of unpaired surface electrons within the frame of the classical model of paramagnetism. Noncompliance with the Curie’s law is observed for the temperature dependences of magnetic characteristics. Injection of moisture in the dispersing medium leads to a decrease of the magnetic characteristics. The samples of quartz powder discovered the effect of increasing the magnetic susceptibility with increasing temperature above 0 °C, unexplained in the framework of the classical theory. The nature of the spin paramagnetism of dispersed structures and the cooperativity evidence in the paramagnetism formation is established in the article. Spin paramagnetism is stipulated by the appearance of unpaired spin magnetic moments due to the electron-pair bond rupture at the moment of dispergating. Bond rupture occurs as on the surface of the dispersion medium granules, and within the scope of the granules in the amorphization of the crystal structure process. The cooperativity is manifested in the appearance of magnetic clusters with parallel oriented spins as a result of spin-spin interaction. The orientation of the clusters magnetic moments occurs in an external magnetic field.

Keywords

dispersed medium, spin paramagnetism, magnetic susceptibility, magnetization
Download (pdf, 4MB )

References

  1. Volosnev A.S., Kozlov A.N., Nekhoroshev A.V., Sinel’nikova S.E., Skovorodkin Yu.P. Magnetizm melkodispersnoy sistemy kremnezem – voda [Magnetism of Silica – Water Fine]. Doklad AN SSSR [Report USSR Acad. Sci.], 1987. Vol. 296, no. 3, pp. 558–560.
  2. Barinov V.A. Magnitnye svoystva razuporyadochennykh i amorfnykh poroshkov, poluchennykh mekhanicheskim izmel’cheniem: dis. … kand. fiz.-mat. nauk [Magnetic Properties of Disordered and Amorphous Powders Prepared by Mechanical Grinding: Cand. Phys. and Math. Sci. Diss.]. Sverdlovsk, 1986. 171 p.
  3. Koposov G.D., Il’in V.A., Sofronov E.L. Inversiya znaka magnitnoy vospriimchivosti pri dispersirovanii materialov [Sign Inversion of the Magnetic Susceptibility at Dispersion of Materials]. Fizichesky vestnik Pomopskogo univ.: sb. nauch. trudov. Arkhangelsk, 2002. Iss. 1, pp. 65–67.
  4. Koposov G.D., Bardyug D.Yu., Sofronov E.L., Sidorov D.B. Vlazhnostnye i polevye zavisimosti magnitnoy vospriimchivosti drevesnoy muki [Humidity and Field Dependences of the Magnetic Susceptibility of Wood Flour]. Fizichesky vestnik Pomopskogo univ.: sb. nauch. trudov. Arkhangelsk, 2003. Iss. 2, pp. 29–33.
  5. Koposov G.D., Il’in V.A., Sofronov E.L., Samylov A.V. Osobennosti magnitnykh svoystv dispergirovannogo organicheskogo stekla [Features of the Magnetic Properties of the Dispersed Organic Glass]. Fiz. vestnik Pomopskogo univ.: sb. nauch. trudov. Arkhangelsk, 2003. Iss. 2, pp. 33–37.
  6. Koposov G.D. Osobennosti ispol’zovaniya metoda Gui pri izuchenii magnitnykh svoystv nelineynykh slabomagnitnykh magnetikov [Gouy Method Usage Pattern in Studies of Magnetic Properties of Nonlinear Weakly Magnetic Materials]. Fiz. vestnik Pomopskogo univ.: sb. nauch. trudov. Arkhangelsk, 2003. Iss. 2, pp. 37–42.
  7. Koposov G.D., Il’in V.A., Veselkov A.Yu., Sofronov E.L. Osobennosti vlazhnostnykh zavisimostey paramagnetizma dispersnykh sred s kremniysoderzhashchimi granulami [Features of Humidity Dependencies of Dispersing Medium with the Siliceous Granules Paramagnetism]. Vestnik Pomopskogo univ., 2004, no. 1, pp. 88–92.
  8. Borovik E.S., Eremenko V.V., Mil’ner A.S. Lektsii po magnetizmu [Lectures on Magnetism]. Moscow, 2005. 512 p.