. 2018 May 15;6:159. doi: 10.3389/fchem.2018.00159
Copyright © 2018 Wang, Luo, Zheng, He, Tong and Yu.
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Figure 4.
X-ray photoelectron spectra of sample A, B, and C [(A) O, (B) Ni, (C) Co, (D) Mn].