R. Sbiaa, H. Meng and S. N. Piramanayagam
This Focus Issue on “Spintronics and Spin Physics” aims at taking a snapshot of ongoing diverse and high-level spin physics and nanomagnetism research trends. Spintronics has long achieved real-world application in hard-disk drives, and yet the topic literally got a new spin after the discovery of the spin-transfer torque effect which led to a revival of research on magnetic random access memories (MRAMs), magnetic logic devices, domain wall memories, etc.
In their Review@RRL (pp. 413–419), R. Sbiaa, H. Meng, and S. N. Piramanayagam give an overview of the development of materials with perpendicular magnetic anisotropy that are crucial for MRAM and other spintronics applications. In particular, for a spin-transfer torque MRAM design the five conflicting criteria of high signal, low resistance, high thermal stability, low writing current, and CMOS integration need to be met, the so-called MRAM pentalemma.