An Inexpensive Route to Synthesize High-Purity CrO2 for EMI Shielding in X-Band Frequencies

Abstract

Rod-shaped high-purity samples of CrO 2 have been synthesized by an inexpensive and simplified procedure. Here, we have prepared pure CrO 2 without applying any external pressure or control it during synthesis. The sample prepared exhibited an improvement in saturation magnetization values, 68 emu/g at 300 K, 136 emu/g at 80 K, and uniform grained microstructure. The complex permittivity, permeability, and microwave absorption properties of high-purity CrO 2 sample were investigated in the 8.2-12.2 GHz (X-band) microwave frequency range. Microwave measurements have shown the high shielding effectiveness due to absorption (SE A ) of 20.3 dB. The high value of SE A suggests that CrO 2 can be used as a promising electromagnetic shielding, EMI, material in 8.2-12.2 GHz (X-band) microwave frequency range.

Enhanced room-temperature magnetoresistance in self-assembled Ag-coated multiphasic chromium oxide nanocomposites

“…Such a unique ferromagnetic oxide in which one spin species is semiconducting and the other metallic has received enormous research interest due to its promising applications, particularly in the emerging areas of spintronics and magneto-optics. [7][8][9][10][11][12][13][14][15][16][17][18][19] In such half-metallic systems, electrical conduction is carried out entirely by charge carriers of a particular spin orientation, i.e., the conduction electrons are completely spin polarized (ideally at B5 K). 20,21 This distinct property of spin polarization of charge carriers makes CrO 2 the most suitable to be utilized not only as a polarizer for spin injection into semiconductors, which is the primary requirement in magnetic tunnel junctions and other spin-dependent devices, but also to develop efficient magneto-optical devices, and even in self-assembled quantum computers.…”