Faraday effect in polycrystalline Mn-doped InSb for LWIR applications

The Faraday rotation (FR) in Mn-doped InSb (Mn-InSb) depends on extremely low doping of Mn into the InSb lattice. The polycrystalline Mn-InSb was prepared by direct alloying of InSb and Mn2Sb, followed by slow cooling of the melt. X-ray diffraction confirms the incorporation of Mn into the In sites, whereas the non-uniform precipitation of MnSb micro-nanoprecipitates was observed via SEM images. The FR of Mn-InSb was measured at room temperature in the 8 to 12 µm spectral range and compared to commercially-available undoped InSb as well as Te-doped InSb (Te-InSb) references and found to be about 1.27 - 1.35 times stronger than that of Te-InSb measured under the same conditions.