Negative refractive index in ferromagnetic semiconductors: experimental verification

摘要

In this work, we show that natural crystals, or magnetic semiconductor, Cr-doped indium oxide, has anegative refractive index at ~ 27.8 micron wavelength. The effect was predicted by two of us a few yearsago (A.G. Kussow and A. Akyurtlu, Phys. Rev. B, 78, 205202 (2008)). Our result seriously undermineswide-spread opinion that only composite artificial metamaterials can demonstrate negative refractive index.Thin ferromagnetic films of ICO were fabricated by original post-annealing sputtering method. FTIR R andT measurements were processed to extract refractive index within the range of interest. The extracted fromcombined transmittance and reflectance FTIR data negative refractive index band parameters are found tobe close to expected one.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.