Coexistence of singlet and ordered S=12 moments in the ground state of the triclinic quantum magnet CuMoO4

S. Haravifard, K. Fritsch, T. Asano, J. P. Clancy, Z. Yamani, G. Ehlers, T. Nishimura, Y. Inagaki, T. Kawae, I. Swainson, B. D. Gaulin

研究成果: ジャーナルへの寄稿記事

抄録

CuMoO4 is a triclinic quantum magnet based on S=1/2 moments at the Cu2+ site. It has recently attracted interest due to the remarkable changes in its chromic and volumetric properties at high temperatures and in its magnetic properties at low temperatures. This material exhibits a first-order structural phase transition at TC ∼ 190 K as well as a magnetic phase transition at TN ∼ 1.75 K. We report low-temperature heat capacity measurements as well as extensive elastic and inelastic neutron scattering measurements on powder samples taken above and below TN. We observe neutron diffraction consistent with a simple (1/2, 0, 0) antiferromagnetic structure indicating a doubling of the a-axis periodicity below TN. In addition, inelastic neutron scattering above a spin gap of ∼2.3 meV is consistent with triplet excitations out of paired S=1/2 moments which form singlet dimers. Low-lying spin wave excitations are also observed and these originate from ordered S=1/2 moments below T N. Taken together these measurements show the ground state of CuMoO4 to display both nonmagnetic singlets and ferromagnetically coupled spins coexisting within an antiferromagnetic structure below T N ∼ 1.75 K.

元の言語英語
記事番号094436
ジャーナルPhysical Review B - Condensed Matter and Materials Physics
84
発行部数9
DOI
出版物ステータス出版済み - 9 22 2011

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Ground state
Magnets
Inelastic neutron scattering
magnets
moments
ground state
inelastic scattering
neutron scattering
Phase transitions
Spin waves
wave excitation
Neutron diffraction
Dimers
Powders
Temperature
magnons
atomic energy levels
Specific heat
neutron diffraction
periodic variations

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

これを引用

Coexistence of singlet and ordered S=12 moments in the ground state of the triclinic quantum magnet CuMoO4. / Haravifard, S.; Fritsch, K.; Asano, T.; Clancy, J. P.; Yamani, Z.; Ehlers, G.; Nishimura, T.; Inagaki, Y.; Kawae, T.; Swainson, I.; Gaulin, B. D.

:: Physical Review B - Condensed Matter and Materials Physics, 巻 84, 番号 9, 094436, 22.09.2011.

研究成果: ジャーナルへの寄稿記事

Haravifard, S. ; Fritsch, K. ; Asano, T. ; Clancy, J. P. ; Yamani, Z. ; Ehlers, G. ; Nishimura, T. ; Inagaki, Y. ; Kawae, T. ; Swainson, I. ; Gaulin, B. D. / Coexistence of singlet and ordered S=12 moments in the ground state of the triclinic quantum magnet CuMoO4. :: Physical Review B - Condensed Matter and Materials Physics. 2011 ; 巻 84, 番号 9.
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abstract = "CuMoO4 is a triclinic quantum magnet based on S=1/2 moments at the Cu2+ site. It has recently attracted interest due to the remarkable changes in its chromic and volumetric properties at high temperatures and in its magnetic properties at low temperatures. This material exhibits a first-order structural phase transition at TC ∼ 190 K as well as a magnetic phase transition at TN ∼ 1.75 K. We report low-temperature heat capacity measurements as well as extensive elastic and inelastic neutron scattering measurements on powder samples taken above and below TN. We observe neutron diffraction consistent with a simple (1/2, 0, 0) antiferromagnetic structure indicating a doubling of the a-axis periodicity below TN. In addition, inelastic neutron scattering above a spin gap of ∼2.3 meV is consistent with triplet excitations out of paired S=1/2 moments which form singlet dimers. Low-lying spin wave excitations are also observed and these originate from ordered S=1/2 moments below T N. Taken together these measurements show the ground state of CuMoO4 to display both nonmagnetic singlets and ferromagnetically coupled spins coexisting within an antiferromagnetic structure below T N ∼ 1.75 K.",
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T1 - Coexistence of singlet and ordered S=12 moments in the ground state of the triclinic quantum magnet CuMoO4

AU - Haravifard, S.

AU - Fritsch, K.

AU - Asano, T.

AU - Clancy, J. P.

AU - Yamani, Z.

AU - Ehlers, G.

AU - Nishimura, T.

AU - Inagaki, Y.

AU - Kawae, T.

AU - Swainson, I.

AU - Gaulin, B. D.

PY - 2011/9/22

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N2 - CuMoO4 is a triclinic quantum magnet based on S=1/2 moments at the Cu2+ site. It has recently attracted interest due to the remarkable changes in its chromic and volumetric properties at high temperatures and in its magnetic properties at low temperatures. This material exhibits a first-order structural phase transition at TC ∼ 190 K as well as a magnetic phase transition at TN ∼ 1.75 K. We report low-temperature heat capacity measurements as well as extensive elastic and inelastic neutron scattering measurements on powder samples taken above and below TN. We observe neutron diffraction consistent with a simple (1/2, 0, 0) antiferromagnetic structure indicating a doubling of the a-axis periodicity below TN. In addition, inelastic neutron scattering above a spin gap of ∼2.3 meV is consistent with triplet excitations out of paired S=1/2 moments which form singlet dimers. Low-lying spin wave excitations are also observed and these originate from ordered S=1/2 moments below T N. Taken together these measurements show the ground state of CuMoO4 to display both nonmagnetic singlets and ferromagnetically coupled spins coexisting within an antiferromagnetic structure below T N ∼ 1.75 K.

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