Giant Controllable Magnetization Changes Induced by Structural Phase Transitions in a Metamagnetic Artificial...

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Controllable metamagnetic transitions from antiferromagnetic (AFM) to ferromagnetic (FM) ordering are crucial for novel spintronics devices.
• Existing spintronics often rely on spin reorientation, but direct control of intrinsic magnetic ordering offers greater potential.
• Iron-rhodium (FeRh) is a promising material for such applications due to its metamagnetic properties.

Purpose of the Study:

• To produce FeRh films with reduced transition temperatures and large magneto-thermal hysteresis for magnetocaloric and spintronics applications.
• To investigate the induction of giant controllable magnetization changes by manipulating strain transfer from a substrate.
• To explore the depth-dependent nature of strain-controlled magnetic order in artificial multiferroic heterostructures.

Main Methods:

• Fabrication of FeRh films on a BaTiO3 (001) single crystal substrate.
• Application of strain through substrate structural phase transitions.
• Characterization of magnetic properties using polarized neutron reflectometry.

Main Results:

• Achieved FeRh films with drastically reduced transition temperatures and large magneto-thermal hysteresis.
• Demonstrated giant controllable magnetization changes (~25%) induced by substrate strain, the largest reported for FeRh.
• Revealed a strong lattice-spin coupling, where surface strain changes trigger massive magnetic transformations, and showed depth-dependent strain control of magnetic order.

Conclusions:

• Strain engineering via BaTiO3 substrate provides a viable method to control magnetic ordering in FeRh films.
• The observed giant magnetization changes and depth-dependent effects open new avenues for designing advanced spintronics and magnetocaloric devices.
• This study highlights the potential of artificial multiferroic heterostructures for realizing controllable magnetic phenomena.