2007 Fiscal Year Final Research Report Summary
Charge and spin ordering in doped quantum spin systems
| Project/Area Number |
17540345
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | Japan Atomic Energy Agency |
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Principal Investigator |
MASASKI Matsuda Japan Atomic Energy Agency, Quantum Beam Science Directorate, Principal researcher (90260190)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Neutron scattering / Spin correlation / Quantum spin system / Frustrated magnet |
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| Research Abstract |
A characteristic feature of the strongly correlated electron system is that it shows interesting phenomena originating from cooperation or competition between orbital, charge and spin degrees of freedom. There are various transition metal oxides that realize the phenomena Neutron scattering technique is a powerful tool to investigate chemical and magnetic structures. We performed neutron scattering experiments to study the spin and charge ordering in interesting transition metal oxides.
First, we studied the effect of hole-doping in high-T_c copper oxides and related compounds, which are doped low-dimensional magnets. We performed neutron scattering experiments on quasi-one-dimensional Ca_<2+x>Y_<2-x>Cu_5O_<10> and quasi-two-dimensional La_<2-x> Sr_xeuO_4. It was found that both systems show a tendency to charge ordering with hole-doping. As the results, antiferromagnetic clusters are formed in Ca_<2+x>Y_<2-x>Cu_5O_<10> and the diagonal stripe ordering is realized in lightly-doped La_<2-x>SrxCuO_4.
We also studied spinel compounds in order to investigate interesting phenomena originating from geometrical frustration. In particular, strong spin-lattice coupling caused by frustration is expected in the compounds. Furthermore, charge and orbital degrees of freedom also give rise to interesting phenomena. We mainly performed neutron scattering experiments in spinel compounds without orbital degree of freedom -to study the pure spin-lattice coupling in the geometrically frustrated system. We clarified chemical and magnetic structures of ACr_2O_2 (A=Cd, Hg) in ambient and high magnetic field and found that magnetic transitions are always accompanied by structural distortions, indicating a strong spin-lattice coupling.
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Research Products
(50 results)
