Project/Area Number |
20740210
|
Research Category |
Grant-in-Aid for Young Scientists (B)
|
Allocation Type | Single-year Grants |
Research Field |
Condensed matter physics II
|
Research Institution | University of Hyogo |
Principal Investigator |
SHUGO Ikeda University of Hyogo, 大学院・物質理学研究科, 助教 (80414580)
|
Project Period (FY) |
2008 – 2011
|
Project Status |
Completed (Fiscal Year 2010)
|
Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2010: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2009: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2008: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
|
Keywords | 巨大磁気抵抗 / 金属絶縁体転移 / 5f電子 / カルコゲナイド化合物 / β-US_2 / USeS / 磁気ポーラロン / EuFe_2As_2 / カルコゲナイド元素 |
Research Abstract |
We studied the physical properties of UXS (X:S, Se, Te) with an orthorhombic crystal structure by measuring its magnetization, magnetic susceptibility, specific heat, and electrical resistivity under magnetic field and pressure. The insulating resistivity of β-US_2 markedly changes to a metallic one under a high pressure of 8 GPa similarly to that of the semimetallic Ising-type ferromagnet UTeS with a Curie temperature TC=87 K.A resistivity anomaly was also observed in the temperature dependence of the resistivity under pressure, most likely corresponding to ferromagnetic ordering. From these experimental results, it was concluded that β-US_2 is in the vicinity of ferromagnetic ordering at ambient pressure. Furthermore, we found that the easy-axis magnetization at low fields for H // [001] consists of a linear magnetization based on the 5f-CEF scheme and a ferromagnetic-like magnetization with a saturated moment of 0.042α_β/U. The latter magnetization was analyzed on the basis of the ferromagnetic cluster and discussed from the viewpoint of the magnetic polaron.
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