Precursor synthesis and properties of iron and lithium co-doped cadmium oxide

Lithium and iron co-doped cadmium oxide Cd0.9(Li1-xFex)0.1O (x = 0.1, 0.3, 0.5, 0.7) with NaCl structure has been synthesized using formate of the composition Cd0.9(Li1-xFex)0.1(HCOO)2·2H2O as a precursor. The NMR spectroscopy results demonstrate that the structure of lithium-doped cadmium oxide appears to have impurity centers only of one type. All the synthesized samples show a metal-like conductivity as indicated by the growth of their electrical resistance with temperature increasing in the interval 78–330 K. The study of the magnetic properties of the Cd0.9(Li1-xFex)0.1O samples at 5 and 300 K revealed that they are ferromagnets, whose saturation magnetization increases with the iron concentration both at low and room temperature reaching the maximal values in the samples with a Li and Fe concentration of 3 and 7 at.%, respectively. An enhancement of the iron concentration in Cd0.9(Li1-xFex)0.1O from x = 0.5 to x = 0.7 leads to an abrupt growth of the magnetization from 0.30 to 1.94 emu/g at 5 K and from 0.16 to 1.03 emu/g at 300 K. Iron doping with a simultaneous reduction of the lithium concentration also results in an increase of the band gap. The properties of these compounds are explained on the basis of first-principles calculations of their band structure.The research was carried out within the state assignment of the Ministry of Education and Science of the Russian Federation (theme “Spin”, No. AAAA-A18-118020290104-2), supported in part by “Electrical Engineering” Shanghai class 2 Plateau Discipline, the Government of the Russian Federation (Decree No. 211, Contract No. 02.A03.21.0006), “Electrical Engineering” Shanghai class 2 Plateau Discipline and the National Natural Science Foundation of China (NSFC, Nos. 12074242, 51862032). Absorption spectra were obtained using the equipment at the Center for Joint Use "Spectroscopy and Analysis of Organic Compounds" at the Postovsky Institute of Organic Synthesis, UB RAS. The optical measurements were carried out in accordance with the scientific and research plans and state assignment of the Institute of Solid State Chemistry, UB RAS (Grant No. AAAA-A19-119031890025-9). E.V.C. acknowledges funding by Saint Petersburg State University project for scientific investigations (ID No. 73028629). TPeer reviewe