Microscopic evidence of dimer breaking up in CuO2 chain for Ca-substituted Sr14Cu24O41 compounds

• Published in: Journal of physics. Condensed matter Vol. 19; no. 19; pp. 196224 - 196224 (12)
• Main Authors: Wang, Jun, Zou, Huamin, Guo, Chao, Wang, Lili, Hu, Ni, Shi, Jing
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 16.05.2007; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Physics; Saturation moments and magnetic susceptibilities; Projection method; Strontium oxides; Electron diffraction; Temperature effects; Mismatch lattice; Doping; Spin chain; Copper oxides; Nonstoichiometry; Magnetic properties; Magnetic susceptibility
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/19/19/196224

In this work we measured the temperature dependence of the static magnetic susceptibility for Ca-doped Sr14Cu24O41 compounds, studied the lattice mismatch between a CuO2 chain and a Cu2O3 ladder by using electron diffraction, and found that the magnetic properties and lattice mismatch were sensitive to the Ca content. Applying a modified 'cut and projection' method, it is found that the lattice mismatch induces the dimers in spin chains to be decoupled into free spin Cu2+. Further more, Ca doping makes lattice mismatch larger and more dimers decoupled. The number of dimerized spins and the number of free spins predicted by this method are in good agreement with those obtained by fitting the experimental static susceptibility data. This explanation can be applied not only to the Ca doping cases, but also to the case of oxygen nonstoichiometry.