Journal of Inorganic Materials ›› 2015, Vol. 30 ›› Issue (12): 1273-1277.doi: 10.15541/jim20150218

• Orginal Article • Previous Articles     Next Articles

Low-temperature Synthesis and Characterizations of LaFeAsO Nanocrystals

De-Xing ZHANG1(), Yun-Lei SUN2, Abuduweli ABULIMIT2, Guang-Han CAO2()   

  1. 1. College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China
    2. Department of Physics, Zhejiang University, Hangzhou 310027, China
  • Received:2015-05-08 Revised:2015-06-20 Online:2015-12-20 Published:2015-11-24
  • About author:ZHANG De-Xing. E-mail: zdxzwy@mail.ahnu.edu.cn

Abstract:

LaFeAsO as a parent compound of iron-based superconductor was synthesized at low temperatures. The mixtures of La2O3, LaCl3 and BaFe2As2 were ball-milled and the pressed pellets were sintered at 500℃ in vacuum. And nanocrystals of LaFeAsO were formed during the solid-state reaction. The solid-state reaction temperature for preparing LaFeAsO is 200℃ lower than the literature reported. The average crystallite size of the as-prepared LaFeAsO is less than 100 nm, as estimated by the X-ray diffraction Scherrer formula. Meanwhile, the c axis of the unit cell is increased by 0.001 nm, primarily stemming from the nanosize effect. Electrical resistivity measurement shows that the spin-density-wave anomaly becomes unremarkable, accompanied by a significant decrease in the transition temperature. The phenomena are discussed in terms of crystallite-size effect and the influence of lattice parameters.

Key words: LaFeAsO, low-temperature solid-state reaction, nanocrystals, spin-density wave

CLC Number: 

  • O614