Copper isotopes, mobility

The only known difference between our preparation of Cu20 and that of Garner and co-workers is that we used ammoniacal hydrazine for the reduction of cuprammonium sulfate to copper, whereas they used a mixture of hydrazine and caustic soda this may have produced a pronounced difference in oxygen mobility in the Cu20 finally formed on the Cu surface. A re-examination of the subject with the simultaneous application of both the isotopic and the calorimetric techniques is very desirable. 

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