拉曼光谱
磁化
X射线光电子能谱
离子
氧气
铁磁性
分析化学(期刊)
化学
材料科学
结晶学
核磁共振
凝聚态物理
磁场
物理
有机化学
量子力学
色谱法
光学
作者
Lisa John,S. Murugesan,B. Sundaravel,N. Ambika,Soumee Chakraborty,A. T. Sathyanarayana,T. R. Ravindran,N. Sivaraman,K. I. Gnanasekar
标识
DOI:10.1002/slct.202302555
摘要
Abstract Molten salt synthesized PdCoO 2 annealed in argon and air exhibits a reversible weight change of about 2.5 %. Le Bail refinements confirm rhombohedral structures without any appreciable change in the lattice parameters for the given weight change. X‐ray photoemission studies show that oxygen uptake/loss did not change the oxidation states of Pd from its nominal +1 state whereas Co 4+ is detected in addition to the Co 3+ and the fraction of Co 4+ increases marginally with oxygen gain. The impact of weight change on the magnetization of PdCoO 2 is very low with a minimum difference. As the low‐spin Co 3+ ions are non‐magnetic, the observed magnetization with a ferromagnetic transition at ~25 K is attributed to the low‐spin Co 4+ ions in the lattice. Raman active bands observed at 700 cm −1 (A 1g ) and 508 cm −1 (E g ) correspond to the Pd−O stretching and bending modes respectively with Co 3+ environment. Additional peaks at 681 and 473 cm −1 with relatively less intensity arise from the weaker Pd−O bond with oxygen linked to Co 4+ .
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