Magnetic properties, chemical and phase composition of thin manganese silicide films fabricated by pulsed laser deposition

Manganese silicide (MnxSiy) thin films with Mn content (CMn) varied from 24 at. % to 52 at. % were grown on i-GaAs (100) substrates. Chemical, phase composition and room temperature magnetic properties of the films were investigated. It was demonstrated that manganese silicide films revealing ferromagnetic properties are multiphase systems. The phases, which are believed to be non-magnetic at room temperature, are compounds with Mn concentration exceeding the average Mn content of the film (higher manganese silicide, MnSi and Mn5Si3). Magnetic properties revealed are attributed with the secondary phases which are Mn doped silicon (Mn:Si) or Mn depleted compounds. For nearly single phase films (with very small 2-nd phase ratio) no room temperature ferromagnetism was observed.