Determination of the atomic coordinations of the substituted light atoms in materials
[ X ]
Tarih
2019
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Natl Inst Optoelectronics
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Light atoms' substitution into a heavy atom coordination in materials can be a difficult process for analysis. Light atoms, which have close ionic radii with the target atom, may sit at the heavy atom's coordination. In such a case, scientist may not differ the signals from the heavy and light atom to differentiate the exact atomic coordinations of the substituted atom. As an example study, boron substitution into the chromium coordinations is studied. In the samples with boron substitution more than 10%, they became polycrystalline material where boron and chromium tended to own their own crystal structures. However, in the samples with lower substitution amounts, for x=0.05 and 0.10, boron atoms seem to sit in the Cr coordinations without any trace from boron atoms. The boron signals in the XRD patterns has not been detected, and accordingly some hypothesis put forwarded, such as; boron sat in the Cr coordinations or cause defects/impurities that can not be detected in patterns due to low amount of the light atoms. Studies were carried on a series of Li-ion battery cathode materials with the general formula LiCr1-xBxO2. The analysis were performed by the x-ray absorption fine structure (XAFS) technique. As a result of the study, 10% boron substitution was determined as a treshold to protect the LiCrO2 crystal structure.
Açıklama
Anahtar Kelimeler
Crystal structure, Electronic structure, Li-ion battery, Oxides, XAFS
Kaynak
Journal of Optoelectronics and Advanced Materials
WoS Q Değeri
Q4
Scopus Q Değeri
Q4
Cilt
21
Sayı
5-6
