THE EFFECT OF SMALL SUBSTITUTIONS OF Gd ON THE MAGNETIC PROPERTIES OF SYSTEM Y〖(〖Co〗_(1-x) 〖Al〗_x)〗_2

Yıl 2017, Cilt: 12 Sayı: 4, 34 - 38, 27.10.2017

Zaur Gamishidze

Öz

Compound  is a zonal metamagnet. It was found that
partial substitution of cobalt for aluminum in  leads to a decrease in the matamagnetic transition field and the
emergence of weak zonal ferromagnetism in the system at . This can significantly modify the character of the effect
of rare-earth impurities on the –subsystem. To exclude the
effect of the crystal­li­ne field, gadolinium was used as a magnetizing
element. Hence the magne­tic properties of the system  were studied in this work. We confined
ourselves to the aluminum concentration range () in the
limits of which initial compounds  are paramagnets and undergo a metamagnetic
transition in the field. It is shown that, with an increase in the
concentration of  (with constant concentration of ), the transition from
paramagnetism to ferromagne­tism takes place. When the content of  increases, the area of ferro­magnetism
expands, and the paramagnetic state area shrinks. The behavior of the compounds
under study in the field depends on the ratio between the degrees of
magnetization of cobalt  and gadolinium  subsystems. If in a weak field is greater than
, gadolinium impurities shift
the metamagnetic transition field towards weak fields, as the molecular field
acting on cobalt from the gadolinium subsystem is summed with the external
magnetic field . In case  in a weak field is smaller than ,  and  are directed anti­para­llel to each other. 

Anahtar Kelimeler

metamagnetizm, magnetization, susceptibility, density of sta¬tes

Kaynakça

• Levitin, R.Z. and Markosyan, A.S., (1988). Usp. Fiz. Nauk 155, 623 [Sov. Phys. Usp. 31, 730 (1988)].
• Goto, T., Fukamichi, K., Sakakibara, T., (1989). Komatsu H. Sol. St. Comm. Vol:72, pp:945.
• Mater, (1991). Vol:3, pp:2515.
• Bloch, D., Edwards, D.M., Shimisu, M., and Voiron, J.J., (1975). Phys. F. Vol:5, pp:1217.
• Kirchmaier, K.R. and Poldi, K.A., (1982). Physics and Chemistry of Rare-Earth Elements, K.A. Gschneider and L. Airing, eds., Moscow: Metallurgiya.
• Duc, N.H., Hien, T.D., Brommer, P.E., and France, J.J., (1998). M.L. Phys. F. Vol:18, pp:275.
• Aleksandryan, V.V., Lagutin, A.S., Levitin, R.Z., at al., (1985). Zh. Eksp. Teor. Fiz. 89:271. [Sov. Phys. JETP 62, 153.
• Ballou, R., Barbara, B., Gamishidze, Z.M., Lemaire, R., Levitin, R.Z., Markosyan, A.S., Magn, J., (1993). Magn. Mater. 119, 294.
• Goto, T., Aruga Katori, H., Koui, K., Levitin, R.Z., Markosyan, A.S., and Gamishidze, Z.M., (1994). Field Induced Transitions of Y_(1-t) 〖Gd〗_t 〖(〖Co〗_(1-0.93) 〖Al〗_0.07)〗_2 in Ultrahigh Magnetic Fields up tu 100T, Phys B 201.
• Tjiablikov, S.V., (1965). In: Methods of Quantum Theory of Magnetism (Niuka, Moscow, 1965) in Russian.