Ferrimagnetic Heusler tunnel junctions with fast spin-transfer torque switching enabled by low magnetization
Chirag Garg, Panagiotis Ch. Filippou, Ikhtiar, Yari Ferrante, See‐Hun Yang, Brian Hughes, Charles Rettner, Timothy Phung, Sergey V. Faleev, Teya Topuria, Mahesh G. Samant, Jae-Uk Jeong, S. Parkin
Abstract
Abstract Magnetic random-access memory that uses magnetic tunnel junction memory cells is a high-performance, non-volatile memory technology that goes beyond traditional charge-based memories. Today, its speed is limited by the high magnetization of the memory storage layer. Here we prepare magnetic tunnel junction memory devices with a low magnetization ferrimagnetic Heusler alloy Mn 3 Ge as the memory storage layer on technologically relevant amorphous substrates using a combination of a nitride seed layer and a chemical templating layer. We switch the magnetic state of the storage layer with nanosecond long write pulses at a reliable write error rate of 10 −7 and detect a tunnelling magnetoresistance of 87% at ambient temperature. These results provide a strategy towards lower write switching currents using ferrimagnetic Heusler materials and, therefore, to the scaling of high-performance magnetic random-access memories beyond those nodes possible with ferromagnetic memory layers.