Tuesday, May 14, 2013

Wrong sample causes retraction

From Retraction Watch, a very interesting explanation from a Chinese group (Yang, UST-China, Hefei):
We recently published a paper entitled “s-wave superconductivity in Ba-doped phenanthrene as revealed by specific-heat measurements.” The sample studied in that paper as Ba1.5-doped phenanthrene is now found to be La-doped phenanthrene. This error was caused by mislabeling the La-doped phenanthrene sample as Ba1.5-doped phenanthrene. During our experiment, we synthesized La- and Ba-doped phenanthrene in the same furnace because both of them have the same sintering temperatures and procedures. The mislabeling occurred when the samples were taken out of the furnace with incorrect records. In addition, it is now found that both Ba- and La-doped phenanthrene show similar superconducting transition temperatures. 
In an earlier paper, we reported superconductivity in Ba-doped phenanthrene. At that time, we had not yet begun synthesizing La-doped phenanthrene samples, so it was impossible to have made a similar mislabeling error. Furthermore, we burned the superconducting Sr-doped and Ba-doped phenanthrene samples reported in the earlier paper at 750°C in air for 2 h and found that the final products were SrCO3 and BaCO3, respectively, which definitely proves that the samples in the earlier paper, indeed, have the composition reported there. 
We are sorry for this error, and we ask that the paper not be regarded as part of the scientific literature. The data in the retracted paper with the correct reanalysis may be reported in a different paper, and the conclusions could be considered valid for La-doped phenanthrene.
Assuming that this is an accurate reporting, I am in some amount of sympathy with the authors. Mislabeling of samples happens -- but it shouldn't make it all the way into a paper.  


  1. Sadly my first reaction is "At least it's not plagiarism."

  2. Unstable IsotopeMay 15, 2013 at 10:06 AM

    Pretty embarrassing that it had to be noticed by journal readers.

  3. I had a case almost like that - a coworker sent us a few samples to try (neither of them did anything interesting). After the paper was published it turned out that the vials were mislabeled. The guy was a total douche about it, insisting that things like that could never, never, never happen on his side.

  4. I hear Daniel Powter's "Bad Day" in the background.

    "Sometimes the system goes on the blink
    And the whole thing turns out wrong"