000202408 001__ 202408
000202408 005__ 20181203023632.0
000202408 0247_ $$2doi$$a10.1103/PhysRevB.90.054418
000202408 022__ $$a1098-0121
000202408 02470 $$2ISI$$a000341163200002
000202408 037__ $$aARTICLE
000202408 245__ $$aSpin dynamics and magnetoelectric properties of the coupled-spin tetrahedral compound Cu2Te2O5Cl2
000202408 260__ $$aCollege Pk$$bAmer Physical Soc$$c2014
000202408 269__ $$a2014
000202408 300__ $$a7
000202408 336__ $$aJournal Articles
000202408 520__ $$aWe report on the spin dynamics and discovery of magnetoelectricity in the coupled-spin tetrahedral compound Cu2Te2O5Cl2. Te-125 NMR measurements show an anomalous resonance frequency shift and a signal wipe-out phenomenon around the Neel temperature T-N = 18.2 K, which could be attributed to the anomalous critical slowing down of the Cu spin fluctuations on the NMR time scale (similar to 10-100 MHz). The critical exponent of (T1T)(-1) proportional to (T - T-N)(-alpha) is 0.40 +/- 0.03, as compared to 0.5 for a three-dimensional mean-field model. This is in contrast to the Br compound [S.-H. Baek et al., Phys. Rev. B 86, 180405 (2012)], which exhibits pronounced singlet dynamics with a large spin gap. Electric polarization (P-c) is observed along the c axis for temperatures below T-N under finite magnetic field but not sensitive to the electric poling. P-c increases sharply over zero to 2T and then reaches saturation. Below T-N, P-c changes its sign depending on the applied magnetic field direction, positive for the H perpendicular to c axis and negative for H parallel to c axis. We discuss possible explanations for the observed magnetoelectric (ME) behavior in terms of linear ME effect, spin-driven multiferroicity, and an exchange striction of intertetrahedral exchange paths involving the Te4+ lone-pair ions. Our results suggest that Cu2Te2O5Cl2 is a type of ME material whose properties are tuned by intertetrahedral exchange interactions involving polarizable Te4+ ions.
000202408 700__ $$aBesara, T.$$uFlorida State Univ, Dept Chem & Biochem, Tallahassee, FL 32306 USA
000202408 700__ $$aChoi, E. S.$$uFlorida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA
000202408 700__ $$aChoi, K. -Y.$$uChung Ang Univ, Dept Phys, Seoul 156756, South Korea
000202408 700__ $$aKuhns, P. L.$$uFlorida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA
000202408 700__ $$aReyes, A. P.$$uFlorida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA
000202408 700__ $$aLemmens, P.$$uTech Univ Carolo Wilhelmina Braunschweig, Inst Condensed Matter Phys, D-38106 Braunschweig, Germany
000202408 700__ $$0240360$$aBerger, H.$$g104502
000202408 700__ $$aDalal, N. S.$$uFlorida State Univ, Dept Chem & Biochem, Tallahassee, FL 32306 USA
000202408 773__ $$j90$$k5$$tPhysical Review B
000202408 909C0 $$0252170$$pLSE$$xU10153
000202408 909CO $$ooai:infoscience.tind.io:202408$$pSB$$particle
000202408 917Z8 $$x107920
000202408 937__ $$aEPFL-ARTICLE-202408
000202408 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000202408 980__ $$aARTICLE