Effect of annealing temperature on exchange stiffness of CoFeB thin films

Abstract

We investigate the exchange stiffness constants of 28-nm-thick CoFeB film using Brillouin light scattering. Series of CoFeB films are prepared on the MgO(001) substrate with or without additional 5-nm thick MgO buffer layer, the effect of the annealing temperature on the exchange stiffness constants are studied. We found that the exchange stiffness constant of 400

Control of crystallization and magnetic properties of CoFeB by boron concentration

“…For the MgO-matched growth of CoFeB, a crystallization process of amorphous CoFeB through annealing was introduced 2 , 9 – 11 . And the important roles of boron in this process have been revealed through many previous studies 8 – 19 . Before annealing, boron acts as a glass former to form an amorphous phase of CoFeB to suppresses the formation of crystal structures other than bcc and to cultivates the highly (100) oriented MgO layer 9 – 12 .…”

“…Among these roles of boron, the decrease in the amount of boron in CoFeB due to inter-layer diffusion and subsequent crystallization is the most crucial mechanism for the implementation of MgO-matched bcc crystal of CoFeB. However, most of the studies on this subject have been limited to observing the distribution of boron or comparing relative concentrations using energy dispersive x-ray spectroscopy (EDS), secondary ion mass spectrometry (SIMS), electron energy loss spectroscopy (EELS) or x-ray photoelectron spectroscopy (XPS) 12 , 16 – 19 . There is no study confirming the specific boron concentration at which crystallization of CoFeB occurs, and the effects of remaining boron in CoFeB on the crystallinity after annealing.…”

Magnetization switching diagram of a perpendicular synthetic ferrimagnet CoFeB/Ta/CoFeB bilayer

“…Metallic spintronics based on CoFeB multilayered structures rapidly gains new areas of its application in sensor industry [ [5][6] ], biomedicine, and information technologies [ [7][8]. Magnetic structure of CoFeB single layers a Correspondent author e-mail: morgunov2005@yandex.ru have been studied in detail [ [9][10][11][12][13][14]. Numerous reports on methods for inducing domain walls by electric current [ [15][16], manipulating them [ [17][18][19], and reversing polarity of perpendicularly polarized nanosized single-and multilayer magnets without external magnetic field [ 20 ] by means of local electric fields [ [21][22] and currents [ [23][24][25] ] can be found for single CoFeB magnets.…”

Skyrmion elongation, duplication, and rotation by spin-transfer torque under spatially varying spin current

“…Most researches try to maximize both DMI and exchange interaction to have robust devices against noise [16][17][18]. However in this work less might actually be better, because smaller J and D allow smaller currents to obtain skyrmion elongation.…”