Magnetization behavior of scandium-substituted barium hexaferrite films having uniaxial axis in the film plane

Orientation Growth and Magnetic Properties of BaM Hexaferrite Films Deposited by Direct Current Magnetron Sputtering

“…According to the model proposed by Cho et al, 23 this is a topotactic reaction of Ba atoms diffusing into the epitaxial a-Fe 2 O 3 precursor matrix. Conversely, for films deposited without oxygen addition, the a-Fe 2 O 3 precursor phase is not formed epitaxially, leading to the BaM phase inheriting its random orientation as well, as confirmed by Meng et al 22 As measured by EDS, the Fe to Ba atomic ratio in the sample sputtered without oxygen (~4) significantly deviates from that of BaM phase (12). It thus can be conjectured that the redundant Ba atoms in this sample inhibit the orientation nucleation and growth of the a-Fe 2 O 3 precursor films, and finally lead to the nonmagnetic anisotropy.…”

“…[1][2][3][4][5][6][7][8][9][10] Especially, in-plane c-axis highly oriented BaM film has drawn much attention in recent years for two reasons. One is its higher ferromagnetic resonance (FMR) frequency, about 45% larger than that of outof-plane c-axis oriented films at zero bias field; 11 the other is the minimized in-plane self-demagnetization effects that generally lead to high hysteresis loop squareness (M r /M s ) value, making self-biased operation possible in components utilizing such materials, 12 which holds much promise for further device miniaturization. 13 Also, in-plane c-axis aligned BaM films find application in microwave filters, phase shifters, and delay lines, whose requirements are hardly fulfilled by the out-of-plane c-axis aligned BaM films, which are mainly used in circulators and isolators.…”

“…However, preparation of in-plane c-axis highly aligned BaM films has always been a challenge, and the influence of various processing parameters remains unclear. Although high-quality inplane c-axis oriented BaM films have been successfully prepared using pulsed laser deposition (PLD) 12,[14][15][16] and liquid phase epitaxy (LPE) 11,[17][18][19] techniques, these methods, however, require expensive equipment. In our previous study, inplane c-axis oriented BaM films were fabricated using DC magnetron sputtering, a proven cost-effective method suitable for industrial production, which has a higher deposition rate than radio-frequency (RF) magnetron sputtering.…”

Self-biased planar millimeter wave notch filters based on magnetostatic wave excitation in barium hexagonal ferrite thin films

“…The values indicated are four times lower than those for previous PLD films. 8,9 ͑2͒ There is a very good match between the experimental FMR profiles and the Lorentzian fits. ͑3͒ The theoretical FMR fields match nicely with the experimental values.…”

“…Yoon et al 7,8 were able to use pulsed laser deposition ͑PLD͒ to grow in-plane c-axis oriented BaM films with higher remanence, at a remanent ͑M r ͒ to saturation magnetization ͑M s ͒ ratio of 0.94. Those "in-plane" films, however, had very broad FMR peaks, with a 50-60 GHz peak-to-peak derivative linewidth ⌬H of 1150 Oe or larger.…”