Coupling of stripes to lattice distortions in cuprates and nickelates

✍ Scribed by M. Hücker; G.D. Gu; J.M. Tranquada; M.v. Zimmermann; H.-H. Klauss; N.J. Curro; M. Braden; B. Büchner

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 215 KB
• Volume: 460-462
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2007.03.003

✦ Synopsis

In recent X-ray diffraction experiments on orthorhombic nickelates, we have observed a significant coupling between the stripe correlations and the lattice distortion. In particular, the diagonal charge stripes of this insulating material exhibit a preferred orientation parallel to the orthorhombic a-axis, similar to the diagonal spin stripes in La 2Àx Sr x CuO 4 below the metal-insulator transition. In the light of this finding, we draw a comparison between the lightly doped parts of the phase diagrams of La 2Àx Sr x CuO 4 with low-temperature orthorhombic (LTO) structure, and La 1.8Àx Eu 0.2 Sr x CuO 4 with low-temperature tetragonal (LTT) structure. In La 1.8Àx Eu 0.2 Sr x CuO 4 , a local minimum in the Sr dependence of the LTO/LTT transition temperature, as well as reduced spin-glass transition temperatures, may be indicators for the presence of diagonal charge correlations. Above the metal-insulator transition the LTT phase is suited to pin parallel stripes, while below that transition the LTT phase seems instead to compete with the formation of diagonal stripes.