Ambient Degradation-Induced Spin Paramagnetism in Phosphorene

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Black phosphorus (BP) possesses properties like a direct bandgap, high mobility, and long spin lifetimes at room temperature, making it promising for spintronic applications.
• Inducing a magnetic response in BP is a key challenge for realizing these spintronic applications.

Purpose of the Study:

• To investigate the magnetic properties of black phosphorus (BP) and understand the role of ambient degradation in inducing magnetism.
• To explore the origin and tunability of magnetism in degraded BP.

Main Methods:

• Characterization of magnetic properties of BP under various ambient conditions.
• Measurement of Landau factor (g ≈1.995) to determine the nature of magnetic moments.
• Analysis of the influence of environmental factors (temperature, humidity, light) on magnetism.

Main Results:

• Immediate and inevitable ambient degradation of BP leads to notable paramagnetism.
• Magnetization primarily originates from spin moments, as indicated by the Landau factor.
• The induced magnetism is tunable by altering ambient temperature, humidity, and light intensity.
• Stabilization of magnetism is observed when BP is exposed to argon.
• Vacancies stabilized by oxygen adatoms are the likely source of magnetism.

Conclusions:

• Ambient degradation is a critical factor influencing the magnetic properties of black phosphorus.
• The discovered tunable paramagnetism in degraded BP opens new avenues for spintronic device development.
• Further research is needed to fully understand and leverage BP's magnetism for technological applications.