Fabrication, structural, dielectric and magnetic properties of tantalum and potassium doped M-type strontium calcium hexaferrites

Terahertz Faraday Rotation of SrFe12O19 Hexaferrites Enhanced by Nb Doping

“…In this case, nonmagnetic Nb 5+ ions replacing the Fe ions at 4f 1 and 4f 2 sites (spin-down states) give rise to the increased net magnetic moment together due to the enhanced ferromagnetic exchange coupling along the z -axis via Fe 3+ –O–Nb 5+ bonds. This is consistent with fitted XRD results and agrees well with previous findings that Nb or other diamagnetic ions prefer to enter the octahedral and tetrahedral sites of Fe in hexaferrites, ,− and the intensity of antiferromagnetic exchange interactions is weakened as the oxygen vacancy decreases. , …”

“…It is expected that both SFO and SFN3O possess multidomain structures with the squareness ratio ( M rs = M r / M s ) 0.485 and 0.447, respectively. , A slimmer M – H loop of SFN3O is observed in Figure c compared with SFO. According to the domain wall theory, , where A is the exchange stiffness, H A is the magneto-crystalline anisotropy, M s is the saturation magnetization, and D is the grain size .…”

Poly(dimethylsilylene)diacetylene-Guided ZIF-Based Heterostructures for Full Ku-Band Electromagnetic Wave Absorption

“…The enhanced peak for graphitic carbons is observed when the pyrolysis temperature increases. The grain sizes for graphitic carbons and cubic Co are calculated using the Debye–Scherrer equation. , where K = 0.90, λ = 0.154 nm, θ is the diffraction angle, and β is the full width at half maxima of the most intense peak. The calculated grain sizes of cubic cobalt atoms in Co/Si/C/N-600, Co/Si/C/N-700, and Co/Si/C/N-800 are 15.3, 16.4, and 20.7 nm, respectively, and the dendritic structure gradually grows on the surface of the ZIF-67-based nanocomplex when the temperature increases to 600 °C and above (Figure S4).…”

“…The enhanced peak for graphitic carbons is observed when the pyrolysis temperature increases. The grain sizes for graphitic carbons and cubic Co are calculated using Debye-Scherrer equation 50,61. (3)where K=0.90, λ=0.154 nm, θ is diffraction angle and β is full width at half maxima of the most intense peak (FWHM).…”

“…The enhanced peak for graphitic carbons is observed when the pyrolysis temperature increases. The grain sizes for graphitic carbons and cubic Co are calculated using the Debye−Scherrer equation 50,61.…”