| Project/Area Number |
16340098
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | Gunma University |
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Principal Investigator |
ITO Masahisa Gunma University, Engineering, professor (90124362)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥15,800,000 (Direct Cost: ¥15,800,000)
Fiscal Year 2006: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2005: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2004: ¥12,200,000 (Direct Cost: ¥12,200,000)
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| Keywords | X-rav Magnetic Diffraction / X-rav Magnetic Scatterine / Soin Magnetic Form Factor / Orhital Maggnetic Form Fartor / Spin Density / Orbital Ordering / Perovskite Titanium Oxide / ペロブスカイト酸化物 / 強磁性体 / YTiO_3 |
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| Research Abstract |
Perovskite oxide YTiO_3 has peculiar solid-state properties; it shows orbital ordering and becomes ferromagnetic below 30K. Origin of the both properties is 3d electrons of Ti atoms. The aim of this research is to elucidate the peculiar properties of the perovskite titanium oxide YTiO_3 by using synchrotron radiation X-rays. We utilize two kinds of experimental methods, l) the X-ray magnetic diffraction (XMD) and 2) the magnetic Compton scattering (MCP), which are elastic and inelastic scattering of elliptically polarized synchrotron radiation X-rays by magnetic moments. Wavefunctions of magnetic electrons are observed in the reciprocal lattice space(or its Fourier transformed real space) by the former method, and in the momentum space by the latter method. Concrete purpose of this study is to clarify the ground state of the 3d electrons of Ti atoms in YTiO_3 through direct observation of the electrons orbital by synchrotron radiation.
We have upgraded the XMD experimental system in ord
… More
er to produce magnetic field of over 2T that is needed for saturating the magnetization even along the hard magnetization direction of this compound, as both experimental methods of XMD and MCP require the magnetization of the specimen to be saturated. By this upgrade of the experimental system we ca perform the XMD experiment under the condition in which the magnetization of the specimen crystal is saturated along any crystallographic direction.
We have obtained the following results from the XMD experiment.(1) We could measure spin magnetic form factor for all principal crystallographic axes of YTiO_3.(2) We have succeeded in obtaining three dimensional distribution of spin density of YTiO_3 in the real space for the first time.(3) The obtained spin density distribution was represented very well by the electron distribution of 3d-electons in the t2g state. This would be the first direct observation of a specific 3d electron orbital in the three dimensional real space. In the MCS experiment we could measure the magnetic Compton profile (MCP) of an orbital-ordering ferromagnetic compound for the first time. By comparing the observed MCP with the calculated MCP based on a model wavefunction we could determine the ground-state wavefunction of the 3d electron. In conclusion we could elucidate the ordered orbital (ground state wavefunction) of the 3d electrons of YTiO_3 in the real space and momentum space. Less
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