Surface Laser Architected Magnets (SLAM)

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OPEN 2021
Malibu, California
Project Term:
08/29/2022 - 08/28/2025

Critical Need:

Today’s high-efficiency electric motors are driven by large and expensive permanent magnets. The standard neodymium iron boron (NdFeB) magnets in these motors are prone to degradation and demagnetization at typical operating temperatures of 150-200 °C. The addition of expensive heavy rare earth (HRE) elements, dysprosium (Dy) and terbium (Tb), is used to increase demagnetization resistance at elevated temperatures. HRE elements pose two major cost-related disadvantages, however: (1) HREs constitute 20-30% of the motor’s material costs and (2) the lack of domestic supply of refined HRE is a risk for the U.S. electric motor industry.

Project Innovation + Advantages:

HRL Laboratories’ surface laser architected magnets (SLAM) approach can reduce the use of HRE by locally optimizing the crystallographic orientation of the microstructure on the magnet’s surface. Using laser-based post-processing methods, SLAM magnetically hardens the weakest points on a NdFeB magnet surface against demagnetization, which enables higher torque and more energy efficient motors. By increasing demagnetization resistance, the extent of usable magnetic energy produced at elevated operating temperatures can be increased up to 2X in permanent magnets. Magnet and motor size and mass can be reduced, saving HRE material and motor costs. These magnets will increase motor efficiency, and thereby accelerate the adoption of electric ground and air vehicles, reduce energy demands and greenhouse gases, and reduce the need for non-domestic rare-earth elements.

Potential Impact:

HRL Laboratories and General Motors will develop magnets with double the energy product of state-of-the-art NdFeB magnets at elevated operating temperatures by tailoring magnet surface architecture to resist demagnetization, which will result in increased efficiency electric motors.


Recycled heavy rare earth (HRE) helps to create a resilient U.S.-based energy infrastructure.


Higher-temperature magnets extend a motor range by 9-14%, thus reducing overall energy demands and greenhouse gasses.


SLAM magnets would allow motor manufacturers to reduce motor cost and mass to accelerate adoption of electric ground and air vehicles.


ARPA-E Program Director:
Dr. Philseok Kim
Project Contact:
Mr. Brennan Yahata
Press and General Inquiries Email:
Project Contact Email:


General Motors

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