I, would like to elaborate on my synthesis and storage procedure.

1. Precursors are CoCl2.6H2O, NaBH4 and oleic acid (surfactant) taken in molar ratio 1:2:0.2 respectively.

2. 15 ml of ethanol, 2.8ml of oleic acid diluted with 15 ml of water, and CoCl2.6H2O are mixed with stirring in a three necked round bottom flask for around 2 hours, in a nitrogen atmosphere

3. NaBH4 is mixed in a mixture of 15 ml of ethanol and 15 ml of water, by stirring in air

4. NaBH4 solution is added dropwise, to the earlier mixture, in nitrogen atmosphere and stirring is continued for 1 hr.

5. The black precipitate is washed repeatedly with ethanol, acetone and demineralised water (so as to remove NaCl, which is a byproduct, as well as excess of oleic acid), using ultrasonication and magnetic separation (the precipitate shows excellent response to an NdFeB permanent magnet) [Washing procedure is repeated taking a time of about 5 to 6 hours].

6. The sample is dried at 1000C in a vacuum oven for one hour.

7. It is stored in a vacuum desiccator.

The problem I am facing is, when I take the XRD pattern (immediately), I get an amorphous like structure with a few broad and less intense peaks present at angles corresponding to the fcc phase of Cobalt monoxide CoO. The peaks of fcc, hcp or Є Co phase is completely absent. The EDS spectrum also shows peaks corresponding to Co and Oxygen. Kindly instruct on how should I improve so as to solve the issues of lack of crystallinity as well as oxidation, inspite of storing the sample in vacuum? [All chemicals used are of Sigma make and the expected particle size is around 10 nm]

Have attached the obtained XRD pattern and EDS spectrum. Thanking all, in advance and expecting suggestions to solve the issues.