Modified hydrothermal reaction (MHT) for CoV2O6 center dot 4H(2)O nanowire formation and the transformation to CoV2O6 center dot 2H(2)O single-crystals for antiferromagnetic ordering and spin-flop

作者：Mondal Chanchal; Sasmal Anup Kumar; Yusuf S M; Mukadam M D; Pal Jaya; Ganguly Mainak; Pal Tarasankar^*

来源：RSC Advances, 2014, 4(100): 56977-56983.

DOI：10.1039/c4ra09976a

A modified hydrothermal protocol (MHT) has been adopted for the synthesis of a single-crystal of CoV2O6 center dot 2H(2)O. The crystals grew as a result of prolonged hydrothermal reaction between precursor salts of CoCl2 and ammonium vanadate. At first, the adopted reaction conditions resulted in nanowires of CoV(2)O6 center dot 4H(2)O. Then with increased reaction time, nanowires changed to single crystals of molecular formula CoV2O6 center dot 2H(2)O. The nanowires have lengths of several tens of micrometers and average diameter of 100 nm. The well defined structure crystallizes in the orthorhombic crystal system having space group Pnma and it displays a = 5.5647(2) angstrom, b = 10.6870(5) angstrom, c = 11.8501(5) angstrom, alpha = beta = gamma = 90.00 degrees. Here, each vanadium atom is tetrahedrally connected to four oxygens where two oxygens are connected to vanadium atoms and another two connected to cobalt atoms. Magnetic moment measurement of the nanowires indicates that antiferromagnetic ordering is observed at around 14.9 K and 6.8 K and field induced antiferromagnetic to ferromagnetic (spin-flop-type) transitions have been observed at a low temperature (5-8.8 K) range while these are absent in the as-synthesized single crystals.

• 出版日期2014