Author/Authors :
A. Kitada، نويسنده , , Y. Tsujimoto، نويسنده , , T. Yamamoto، نويسنده , , Y. Kobayashi، نويسنده , , Y. Narumi، نويسنده , , K. Kindo، نويسنده , , A.A. Aczel، نويسنده , , G.M. Luke، نويسنده , , Y.J. Uemura، نويسنده , , Y. Kiuchi، نويسنده , , Y. Ueda، نويسنده , , K. Yoshimura، نويسنده , , Y. Ajiro، نويسنده , , H. Kageyama، نويسنده ,
Abstract :
We will present the synthesis, structure and magnetic properties of a new quadruple-layered perovskite (CuCl)Ca2NaNb4O13. Through a topotactic ion-exchange reaction with CuCl2, the precursor RbCa2NaNb4O13 presumably having an incoherent octahederal tliting changes into (CuCl)Ca2NaNb4O13 with a 2ap×2ap×2cp superstructure (tetragonal; a=7.73232(5) Å, c=39.2156(4) Å). The well-defined superstructure for the ion-exchanged product should be stabilized by the inserted CuCl4O2 octahedral layers that firmly connect with neighboring perovskite layers. Magnetic studies show the absence of long-range magnetic ordering down to 2 K despite strong in-plane interactions. Aleksandrov′s group theory and Rietveld refinement of synchrotron X-ray diffraction data suggest the structure to be of I4/mmm space group with in-phase tilting along the a and b axes, a two-tilt system (++0).
Keywords :
Ion-exchange reaction , Magnetism , Quadruple-layered perovskite , (CuCl)Ca2NaNb4O13 , crystal structure , Two-dimensional magnet
