http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Irreversible field-induced magnetic phase transitions and properties of Ho<sub>3</sub>Co
Baranov, N V,Goto, T,Hilscher, G,Markin, P E,Michor, H,Mushnikov, N V,Park, J-G,Yermakov, A A IOP Pub 2005 Journal of physics, an Institute of Physics journa Vol.17 No.21
<P>The results of magnetic susceptibility, magnetization, electrical resistivity and specific heat measurements performed on Ho<SUB>3</SUB>Co single crystals show that this compound exhibits two different antiferromagnetic structures: AF<SUB>II</SUB> at 8 K<<I>T</I>< 22 K and AF<SUB>I</SUB> below <I>T</I><SUB>t</SUB>≈8 K. Below the Néel temperature <I>T</I><SUB>N</SUB> = 22 K the application of a magnetic field along the main crystallographic directions induces magnetic phase transitions which are accompanied by giant magnetoresistance. At <I>T</I><<I>T</I><SUB>t</SUB> the field-induced phase transitions along the <B><I>c</I></B>- and <B><I>b</I></B>-axes are found to be irreversible, and a small ferromagnetic component is observed along the <B><I>a</I></B>-axis. These peculiarities are associated with the non-Kramers character of the Ho ion and with the presence of a complex incommensurate magnetic structure of Ho<SUB>3</SUB>Co below <I>T</I><SUB>N</SUB>. The temperature coefficient of the electrical resistivity for Ho<SUB>3</SUB>Co above <I>T</I><SUB>N</SUB> over a wide temperature range is found to differ from that observed for other R<SUB>3</SUB>Co compounds. Such a behaviour is attributed to the presence of an additional contribution to the conduction electron scattering by spin fluctuations induced by f–d exchange in the itinerant d-electron subsystem. The value of this extra contribution and its temperature range is suggested to depend on the spin value of the R ion. The excess of the effective magnetic moment per R ion, which is observed in Ho<SUB>3</SUB>Co and in other R<SUB>3</SUB>M type compounds, is also attributed to spin fluctuations induced by f–d exchange.</P>