Single-Step Synthesis of Sr4V2O6Fe2As2: The Blocking Layer Based Potential Future Superconductor

• Published in: Journal of superconductivity and novel magnetism Vol. 22; no. 7; pp. 619 - 621
• Main Authors: Pal, Anand, Vajpayee, Arpita, Meena, R. S., Kishan, H., Awana, V. P. S.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.10.2009; Springer
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Letter; Magnetic Materials; Magnetism; Occurrence, potential candidates; Physics; Physics and Astronomy; Strongly Correlated Systems; Superconductivity; As; 74.10.+v; V; 74.70.Ad; Superconductivity; Iron oxy-pnictides; Novel synthesis; Sr; O; Fe; 74.25.Ha; Space groups; Lattice parameters; Iron based oxyarsenide; Superconductors; Solid state crystal growth; Spin density waves
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-009-0494-5

We report synthesis, structural details and transport measurements on Sr 4 V 2 O 6 Fe 2 As 2 . Namely, the stoichiometric amounts of V 2 O 5 +1/2×SrO 2 +7/2×Sr+2×FeAs are weighed mixed, ground thoroughly and palletized in rectangular form in a glove box in high purity Ar atmosphere. The pellet is further sealed in an evacuated (10 −5  torr) quartz tube and put for heat treatments at 750 and 1150°C in a single step for 12 and 36 hours respectively. Finally the quartz ampoule is allowed to cool naturally to room temperature. The as-synthesized sample is black in color. The compound crystallized in P 4/ nmm space group with lattice parameters a = b =3.925 Å and c =15.870 Å. Also seen are some small impurity lines. The compound did not exhibit superconductivity but instead a spin density wave ( SDW ) like metallic step at around 175 K is seen in R ( T ) measurements. Principally in [FeAs] −1 {Sr 4 V 2 O 6 } C [FeAs] −1 the net value of blocking layer charge C must be either less or more than 2, to let it be electron or hole type superconductor respectively. Efforts are under way to achieve superconductivity in the studied system.