Crystal Structure Imperfection of LiFePO4 Synthesized Through Solid-state Reaction: An XRD Overview
Ibrahim Purawiardi,
Christin Rina Ratri
Issue:
Volume 5, Issue 1, March 2020
Pages:
1-6
Received:
5 March 2020
Accepted:
19 March 2020
Published:
31 March 2020
Abstract: Solid-state reaction is one of some methods to synthesize LiFePO4 powder. However, the post-synthesis crystal structure was found to be imperfect, probably caused by the imperfection of the phospho-olivine structure. This study aimed to investigate the cause of its imperfection. A LiFePO4 powder synthesized via solid-state reaction path was used as a case study sample for this study. XRD characterization was done to investigate it. Orthorhombic crystal structure was found to be a perfect fit for this sample using precise lattice parameter analysis, as shown by the linear regression equation result. Further analysis was performed using Rietveld refinement method to pinpoint the actual coordinates of Li, Fe, P, and O atoms. The result shows that solid-state reaction can produce an order of orthorhombic crystal structure which constructed by ordered Li atoms arrangement. On the other hands, there is a disordered phospho-olivine structure due to the imperfection of the occupation of Fe, P, and O atoms. These disorders were found through analysis of anomalous peaks on the Rietveld refinement result when compared with PDF database. Loss of (200) plane was caused by imperfect occupation of O atoms, while imperfect occupation of Fe and P atoms leads to new (200) plane of FeP4 phase which has a monoclinic crystal structure.
Abstract: Solid-state reaction is one of some methods to synthesize LiFePO4 powder. However, the post-synthesis crystal structure was found to be imperfect, probably caused by the imperfection of the phospho-olivine structure. This study aimed to investigate the cause of its imperfection. A LiFePO4 powder synthesized via solid-state reaction path was used as...
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Geochronology of Two Mafic Intrusions in Funing, Yunnan: Implications for Its Relationships with Carlin-like Gold Mineralization
Pi Qiaohui,
Wei Chaowen,
Yu Huidong,
Lu Di
Issue:
Volume 5, Issue 1, March 2020
Pages:
7-19
Received:
26 February 2020
Accepted:
17 March 2020
Published:
8 April 2020
Abstract: The relationship between mafic intrusion and gold deposits has always received substantial attention. Based on the petrography, mineralogy, and chronology of two mafic intrusion suites exposed in the Funing area, we found that the mafic intrusion suites have closely relationship with gold mineralization. The 255±4.9-Ma U-Pb age of the early mafic intrusion suite is much older than the 218.9±6.4-Ma (MSWD=1.2) U-Pb age of the late mafic intrusion suite. Based on previous studies on former gold mines in the area, it is believed that early mafic intrusion suite appears to have contributed to the early hydrothermal enrichment of gold deposits through the action of water-rock, together with atmospheric precipitation and stratigraphic water. Due to favorable structural conditions during the Indosinian tectonic period, the late basic rock not only extracted metallogenic materials from the stratum but also acted as an important heat source for the metallogenic fluid circulation and mineralization, together with superposed mineralization of frequent tectonic activities on early deposits, finally forming into ore deposits in favorable structures. Therefore, we believe that the mafic intrusion suite in the late period of the region are closely related to the gold mineralization in the region, and it can be used as a prospecting mark for gold deposits in the area.
Abstract: The relationship between mafic intrusion and gold deposits has always received substantial attention. Based on the petrography, mineralogy, and chronology of two mafic intrusion suites exposed in the Funing area, we found that the mafic intrusion suites have closely relationship with gold mineralization. The 255±4.9-Ma U-Pb age of the early mafic i...
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