The complex superstructure in Mg1-xAlxB2 at x~0.5

Abstract

Electron diffraction and high resolution microscopy have been performed on Mg1-xAlxB2 with x~0.5. This composition displays a superstructure with a repeat period of exactly 2c along the c axis and about 10 nm in the a-b plane. The superstructure results in ring-shaped superreflections in the diffraction pattern. Irradiation by a strong electron beam results in a loss of the superstructure and a decrease of about 1% in the c lattice parameter. In-situ heating and cooling on the other hand showed that the superstructure is stable from 100 K to 700 K. Possible origins for the superstructure are proposed.

References in corpus (4)

• Superconductivity of metallic boron in MgB_2
• Superconductivity of MgB2: Covalent Bonds Driven Metallic
• Hole Superconductivity in $Mg{B}_2$: a high $T_c$ cuprate without Cu
• Effect of Carbon-Doping in Bulk Superconducting MgB2 Samples

Cited by in corpus (10)

• Crystal Chemistry of Carbon-Substituted MgB2
• Carbon doping of superconducting magnesium diboride
• Al substitution in MgB2 crystals: influence on superconducting and structural properties
• High-pressure synthesis of pure and doped superconducting MgB2 compounds
• Crystal structure of the Mg${}_{1-x}$Al${}_x$B${}_2$ superconductors near x=0.5
• ${}^{11}$B and ${}^{27}$Al NMR spin-lattice relaxation and Knight shift study of Mg${}_{1-x}$Al${}_x$B${}_2$. Evidence for anisotropic Fermi surface
• Isotope effect on the E2g phonon and mesoscopic phase separation near the electronic topological transition in Mg1-xAlxB2
• A magnetization and ${}^{11}$B NMR study of Mg${}_{1-x}$Al${}_x$B${}_2$ superconductors
• Aluminium substitution induced superstructures in Mg1-xAlxB2 (x = 0.0 to 0.50): An X-ray diffraction study
• Ab initio modeling of superconducting alloys