Apostolova Iliana N, Apostolov Angel T, Wesselinowa Julia Mihailowa
University of Forestry, Kl. Ohridsky Blvd. 10, 1756 Sofia, Bulgaria.
University of Architecture, Civil Engineering and Geodesy, Hr. Smirnenski Blvd. 1, 1046 Sofia, Bulgaria.
Materials (Basel). 2024 Apr 23;17(9):1945. doi: 10.3390/ma17091945.
Using a microscopic model and Green's function theory, we calculated the magnetization and band-gap energy in ion-doped LiPO (LPO), where = Fe, Ni, Co, Mn. Ion doping, such as with Nb, Ti, or Al ions at the Li site, induces weak ferromagnetism in LiFePO. Substituting Li with ions of a smaller radius, such as Nb, Ti, or Al, creates compressive strain, resulting in increased exchange interaction constants and a decreased band-gap energy, Eg, in the doped material. Notably, Nb ion doping at the Fe site leads to a more pronounced decrease in Eg compared to doping at the Li site, potentially enhancing conductivity. Similar trends in Eg reduction are observed across other LPO compounds. Conversely, substituting ions with a larger ionic radius than Fe, such as Zn and Cd, causes an increase in Eg.
我们使用微观模型和格林函数理论，计算了离子掺杂的LiPO（LPO，其中 = Fe、Ni、Co、Mn）中的磁化强度和带隙能量。离子掺杂，例如在锂位点用Nb、Ti或Al离子进行掺杂，会在LiFePO中诱导出弱铁磁性。用半径较小的离子（如Nb、Ti或Al）替代Li会产生压缩应变，导致掺杂材料中的交换相互作用常数增加，带隙能量Eg降低。值得注意的是，与在锂位点掺杂相比，在铁位点进行Nb离子掺杂会导致Eg更显著地降低，这可能会提高导电性。在其他LPO化合物中也观察到了类似的Eg降低趋势。相反，用比Fe离子半径更大的离子（如Zn和Cd）进行替代会导致Eg增加。
