Competing lattice fluctuations and magnetic excitations in CuO

被引：11

作者：

Choi, K. -Y. ^{[1
]}

Lee, W. -J. ^{[1
]}

Glamazda, A. ^{[1
]}

Lemmens, P. ^{[2
]}

Wulferding, D. ^{[2
]}

Sekio, Y. ^{[3
]}

Kimura, T. ^{[3
]}

机构：

[1] Chung Ang Univ, Dept Phys, Seoul 156756, South Korea

[2] TU Braunschweig, Inst Condensed Matter Phys, D-38106 Braunschweig, Germany

[3] Osaka Univ, Grad Sch Engn Sci, Div Mat Phys, Toyonaka, Osaka 5608531, Japan

来源：

PHYSICAL REVIEW B | 2013年 / 87卷 / 18期

基金：

新加坡国家研究基金会;

关键词：

LIGHT-SCATTERING;

D O I：

10.1103/PhysRevB.87.184407

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Lattice vibrations as well as magnetic excitations are investigated using Raman scattering to understand the high-T-c multiferroic properties of CuO. We observe a flat, broad spinon continuum extending to 2800 cm(-1), being superimposed by magnon excitations with energies below 1350 cm(-1). This allows us to estimate an exchange coupling constant of J = 108 meV. Three Raman-active phonon modes predicted by lattice dynamical calculations are assigned and analyzed. We find a crossover temperature T* = 140-150 K through which new phonon modes are activated and phonon parameters show appreciable anomalies. This feature is discussed in terms of a competition of polar and nonpolar lattice distortions. Our study suggests the importance of competing lattice fluctuations for multiferroic compounds, which possess an intermediate multiferroic phase.

引用

页数：5

共 26 条

[1] MAGNETIC-STRUCTURE OF CUO BY NEUTRON-DIFFRACTION WITH POLARIZATION ANALYSIS [J].

AIN, M ;

MENELLE, A ;

WANKLYN, BM ;

BERTAUT, EF .

JOURNAL OF PHYSICS-CONDENSED MATTER, 1992, 4 (23) :5327-5337

[2]

[Anonymous], 1962, Phys. Rev, DOI DOI 10.1103/PHYSREV.128.2131

[3] Electric field control of chiral magnetic domains in the high-temperature multiferroic CuO [J].

Babkevich, P. ;

Poole, A. ;

Johnson, R. D. ;

Roessli, B. ;

Prabhakaran, D. ;

Boothroyd, A. T. .

PHYSICAL REVIEW B, 2012, 85 (13)

[4] ANHARMONIC EFFECTS IN LIGHT-SCATTERING DUE TO OPTICAL PHONONS IN SILICON [J].

BALKANSKI, M ;

WALLIS, RF ;

HARO, E .

PHYSICAL REVIEW B, 1983, 28 (04) :1928-1934

[5] ANTIFERROMAGNETISM IN CUO STUDIED BY NEUTRON POLARIMETRY [J].

BROWN, PJ ;

CHATTOPADHYAY, T ;

FORSYTH, JB ;

NUNEZ, V ;

TASSET, F .

JOURNAL OF PHYSICS-CONDENSED MATTER, 1991, 3 (23) :4281-4287

[6] Multiferroics: a magnetic twist for ferroelectricity [J].

Cheong, Sang-Wook ;

Mostovoy, Maxim .

NATURE MATERIALS, 2007, 6 (01) :13-20

[7] Anomalous low-energy phonons in nearly tetragonal BiFeO3 thin films [J].

Choi, K. -Y. ;

Do, S. H. ;

Lemmens, P. ;

Wulferding, D. ;

Woo, C. S. ;

Lee, J. H. ;

Chu, K. ;

Yang, C. -H. .

PHYSICAL REVIEW B, 2011, 84 (13)

[8] Critical spin dynamics of the S=1/2 spin chain compound CuSe2O5 [J].

Choi, K. -Y. ;

Lemmens, P. ;

Berger, H. .

PHYSICAL REVIEW B, 2011, 83 (17)

[9] Revival of the magnetoelectric effect [J].

Fiebig, M .

JOURNAL OF PHYSICS D-APPLIED PHYSICS, 2005, 38 (08) :R123-R152

[10] MAGNETISM IN CUPRIC OXIDE [J].

FORSYTH, JB ;

BROWN, PJ ;

WANKLYN, BM .

JOURNAL OF PHYSICS C-SOLID STATE PHYSICS, 1988, 21 (15) :2917-2929

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