Spin susceptibility and superexchange interaction in the antiferromagnet CuO

Shimizu, Tadashi; Matsumoto, Takehiko; Goto, Atsushi; Rao, T. V. Chandrasekhar; Yoshimura, Kazuyoshi; Koyamada, Koji

doi:10.1103/physrevb.68.224433

Cited by 59 publications

(54 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fitted J 1 = -51 meV is in a good agreement with J=67±20 retrieved from neutron scattering experiments [4]. The fitted value of J 2 =8.6 meV, is only about 1/6 of |J 1 |, consistent with quasi-1D model [25], and the fitted value of J 7 =9.87 meV. The fitted intersublattice coupling values J 3 =4.9 meV and J 4 =7 meV are weak, because the Cu-O-Cu bond angles are close to 90…”

Section: −5åsupporting

confidence: 85%

See 1 more Smart Citation

Origin of Ferroelectricity in High-TcMagnetic Ferroelectric CuO

et al. 2012

View full text Add to dashboard Cite

"Magnetic ferroelectric" has been found in a wide range of spiral magnets. However, these materials all suffer from low critical temperatures, which are usually below 40 K, due to strong spin frustration. Recently, CuO has been found to be multiferroic at much higher ordering temperature (∼ 230K). To clarify the origin of the high ordering temperature in CuO, we investigate the structural, electronic and magnetic properties of CuO via first-principles methods. We find that CuO has very special nearly commensurate spiral magnetic structure, which is stabilized via the Dzyaloshinskii-Moriya interaction. The spin frustration in CuO is relatively weak, which is one of the main reasons that the compound have high ordering temperature. We propose that high Tc magnetic ferroelectric materials can be found in double sublattices of magnetic structures similar to that of CuO. PACS numbers: 75.85.+t, Magnetic ferroelectric materials in which ferroelectricity is induced by magnetic ordering, have attracted intensive interests [1,2]. The strong magnetoelectric (ME) coupling in these materials opens up a new path to the design of multifunctional devices that allow the control of charges by the application of magnetic fields or spins by applying voltages. So far, almost all magnetic ferroelectric materials are strongly frustrated magnets [2]. Frustrated magnets have very low ordering temperatures (∼ 30 -40 K), several times smaller than the temperatures expected from their spin interaction strengths. Low critical temperature is one of the major factors that limit the applications of these important materials. Therefore a new mechanism that allows high temperature magnetic ferroelectric materials is critical.Recently, CuO was found to be multiferroic at T c =230 K, which is much higher than the critical temperatures of all other magnetic ferroelectric materials [3]. However, the mechanism for the high ordering temperature were not clear. So far, CuO is the only binary compound that has been found to be multiferroic [3]. CuO undergoes two successsive magnetic phase transitions upon cooling from room temperature to near zero temperature. Neutron scattering experiments [4] show that below T N 1 =213 K, the spin structure is collinear antiferromagnetic (AFM1) [see Fig. 1(a)]. Between T N 1 and T N 2 =230 K, the spin structure becomes non-collinear and slightly incommensurate (AFM2) [see Fig. 1(b)], with a modulation vector of Q= (0.006, 0, 0.017). Remarkably, an electric polarization of 160 µC·m −2 , which can be reversed by applying an electric field of about 55 kV/m, develops in the AFM2 phase. The electric polarization was attributed to the spiral spin structure [3,5] which was assumed to result from spin frustration and whereas the high ordering * Email address: helx@ustc.edu.cn temperature is believed to come from the strong exchange interactions [3].To clarify the mechanism behind its high ordering temperature and the origin of its ferroelectricity, we carry out first-principles studies of the multiferroism of CuO. We find ...

show abstract

Section: −5åsupporting

confidence: 85%

“…• for these two Js [25].In AFM1 and AFM2 phases, symmetry causes additional mutual cancelation of J 3 and J 4 ; therefore, the energy cost of chain II rotation is low, as was discussed in the previous paragraph. We also calculate the next-nearest-neighbor (NNN) interactions J 5 , J 6 .…”

Section: −5åmentioning

confidence: 73%

Origin of Ferroelectricity in High-TcMagnetic Ferroelectric CuO

et al. 2012

View full text Add to dashboard Cite

show abstract

“…In this 2D CuO thin film, the existence of mix valence states and induced defects would be benefit to breaking the long rang magnetic order and forming short-range magnetic order in a wide temperature range, which may induce magnetic fluctuation and enhance magnetic frustration that tends to form a non-collinear spin order at high 6 temperature. This point is consistent with the fact that the short-range magnetic order still remains at high temperature (>550K) and a broadened , 0, peak had been observed even at 290 K in neutron scattering study of 3D CuO single crystal [8,11,12,[30][31][32]. [8].…”

supporting

confidence: 87%

Thermal stimulated current response in cupric oxide single crystal thin films over a wide temperature range

Yang¹,

Wu²,

Yu³

et al. 2016

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Cupric oxide single crystal thin films were grown by plasma-assisted molecular beam epitaxy.X-ray diffraction, Raman spectrum and in situ reflection high-energy electron diffraction show that the thin films are 2×2 reconstructed with an in-plane compression and out-of-plane stretching. Thermal stimulated current measurement indicates that the electric polarization response presents in the special 2D cupric oxide single crystal thin film over a wide temperature range from 130 K to near-room temperature. We infer that the abnormal electric response involves the changing of phase transition temperature induced by structure distortion, the spin frustration and magnetic fluctuation effect of short-range magnetic order, or the combined action of both two factors mentioned above. This work suggests a promising clue for finding new room temperature single phase multiferroics or tuning phase transition temperature.2

show abstract

“…Note that the fit to the reduced temperature depends on j/J rather than J. Neutron scattering has determined J 1 to be between À 75 and À 80 meV, with J 2 ¼ 5 and J 7 ¼ 3 meV 24,43 . Other measurements include |J 1 | ¼ 77 meV from susceptibility 44 , and |J 1 | ¼ 100 meV from mid-infrared conductivity 45 and Raman spectra 46 . Recent DFT calculations have yielded values for J 1 ranging from À 51 to À 127 meV 23,28 .…”

Section: Roommentioning

confidence: 99%

High-temperature electromagnons in the magnetically induced multiferroic cupric oxide driven by intersublattice exchange

et al. 2014

View full text Add to dashboard Cite

Magnetically induced ferroelectric multiferroics present an exciting new paradigm in the design of multifunctional materials, by intimately coupling magnetic and polar order. Magnetoelectricity creates a novel quasiparticle excitation-the electromagnon-at terahertz frequencies, with spectral signatures that unveil important spin interactions. To date, electromagnons have been discovered at low temperature (o70 K) and predominantly in rare-earth compounds such as RMnO 3 . Here we demonstrate using terahertz time-domain spectroscopy that intersublattice exchange in the improper multiferroic cupric oxide (CuO) creates electromagnons at substantially elevated temperatures (213-230 K). Dynamic magnetoelectric coupling can therefore be achieved in materials, such as CuO, that exhibit minimal static cross-coupling. The electromagnon strength and energy track the static polarization, highlighting the importance of the underlying cycloidal spin structure. Polarized neutron scattering and terahertz spectroscopy identify a magnon in the antiferromagnetic ground state, with a temperature dependence that suggests a significant role for biquadratic exchange.

show abstract

Spin susceptibility and superexchange interaction in the antiferromagnet CuO

Cited by 59 publications

References 45 publications

Origin of Ferroelectricity in High-TcMagnetic Ferroelectric CuO

Origin of Ferroelectricity in High-TcMagnetic Ferroelectric CuO

Thermal stimulated current response in cupric oxide single crystal thin films over a wide temperature range

High-temperature electromagnons in the magnetically induced multiferroic cupric oxide driven by intersublattice exchange

Contact Info

Product

Resources

About