Substrate Charge Transfer Induced Ferromagnetism in MnSe/SrTiO3 Ultrathin Films
Chun-Hao Huang1, Chandra Shekar Gantepogu1,2,3, Peng-Jen Chen4
1Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.
Nanomaterials (Basel, Switzerland)
|August 28, 2024
Summary
Superconductivity in manganese selenide (MnSe) ultrathin films was investigated. Strain-induced tetragonal MnSe films on strontium titanate (STO) substrates exhibit enhanced conductivity and superparamagnetism at ambient conditions.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Thin Film Physics
Background:
- Superconductivity observed in MnSe at high pressure (12 GPa) suggests potential for ambient condition superconductivity.
- Strain engineering in ultrathin films is a viable strategy to modify material properties and induce novel phenomena.
Purpose of the Study:
- To investigate the possibility of inducing superconductivity in manganese selenide (MnSe) at ambient conditions.
- To explore the physical properties of MnSe ultrathin films under strain-induced tetragonal phase.
Main Methods:
- Pulsed Laser Deposition (PLD) technique used to prepare MnSe ultrathin films on (001) SrTiO3 (STO) substrates.
- Characterization of structural, magnetic, optical, and electronic properties of the resulting tetragonal MnSe films.
Main Results:
- Tetragonal MnSe ultrathin films on STO exhibit significantly enhanced conductivity compared to bulk or polycrystalline samples.
- Evidence of superparamagnetism observed in the tetragonal MnSe films.
- Optical absorption and X-ray absorption spectroscopy reveal enhanced electron transitions and increased unoccupied valence band states.
Conclusions:
- The strain-induced tetragonal phase in MnSe ultrathin films leads to substantial conductivity enhancement and superparamagnetism at ambient conditions.
- Charge transfer from the SrTiO3 substrate is identified as a key factor in the observed conductivity enhancement and ferromagnetic ordering.
