Size-tunable skyrmion bubbles in Ta/CoFeB/MgO multilayers

Abstract

The stabilization of skyrmion bubbles in [Ta(tTa)/CoFeB(1.1 nm)/MgO(1.0 nm)]15/Ta(2.0 nm) magnetic multilayers with perpendicular magnetic anisotropy is investigated. The size of the skyrmion bubbles can be controlled by tuning the Ta interlayer thickness. Because the perpendicular anisotropy constant is large in samples with a thin Ta interlayer, we can observe nanoscale skyrmion bubbles in our system. This finding provides a means to control the skyrmion size without using an external magnetic field. Moreover, we found that skyrmion bubbles can be created by a magnetic tip and subsequently be deleted. Our novel findings provide insight into skyrmion-based spintronic devices.

Enhancement of zero-field skyrmion density in [Pt/Co/Fe/Ir]2 multilayers at room temperature by the first-order reversal curve

“…These regions will be reversed in the form of circular domains, i.e., the presence of magnetic skyrmions (image 2), as a result of the competition between DMI and demagnetizations. [29][30][31] The estimated diameter of skyrmions in image 2 is about 400∼500 nm. Second, these skyrmion-like domains expand in a non-symmetrical manner and become into short labyrinth stripes with increasing H z (image 3).…”

Multiple Nonvolatile Skyrmion States in Nanostructured Synthetic Antiferromagnetic Multilayers

“…The magnetic skyrmion, a topological nontrivial spin texture, has attracted extensive attention in recent years [1][2][3][4][5]. Considering its advantages of nanoscale size [6][7][8], particlelike features [9][10][11], topological stability [12][13][14][15], and magneto-electric properties [16][17][18][19][20], the skyrmion is expected to be a promising alternative as an information carrier in future functional spintronic devices, such as multilevel memories [21,22], nano-oscillators [23,24], and neuromorphic computing [25][26][27][28][29]. The skyrmion was discovered early in noncentrosymmetric B-20 bulk magnets with the assistance of an external field at low temperature [30].…”

Skyrmion Formation in Nanodisks Using Magnetic Force Microscopy Tip

“…Recently, individual skyrmion manipulation in a Nanomaterials 2021, 11, 2627 2 of 10 Pt/CoFeB/MgO multilayer using a magnetic force microscopy (MFM) tip was reported [14]. This method was also used for the nucleation of domains, skyrmions and skyrmion lattices in various non-patterned ultrathin films [15][16][17][18]. The effect of the magnetization reversal of skyrmions by the MFM tip was studied in symmetric Pt/Co/Pt thin films consisting of modified cylindrical regions with a diameter of 100 nm [19].…”