Carbon encapsulation of ferromagnetic L1oFePt nanocrystals with an enhanced coercivity from distorted lattices

Pyrolysis of ferrocene over Pt coated SiO2 substrate produces L1oFePt encapsulated carbon nanotubes with enhanced magnetic coercivity at room temperarure. The underlying mechanism involves spin pinning by domain boundaries and encapsulation induced lattice distortion along [001] crystallographic plane; the latter is rarely seen and is supported by ab initio calculation. Carbon encapsulation of L1oFePt is achieved through S–C mechanism and only takes place at specific location in pyrolytic furnace.