Magnetization process in FePd thin films

Abstract

A custom made magnetic force microscope is used to study the magnetization process in thin films of FePd throughout the entire hysteresis loop. The 40 nm thick sample has a strong perpendicular anisotropy, which leads to a maze of 80 nm wide stripes of opposite polarity in the remanent state. The growth of M, when H increases, happens through an unwinding of the reversed domain along their axis. Together with the length recession, the reversed domain width also contracts with increasing field. The later effect is estimated by comparison of our images with magneto-optical Kerr measurements. A large disorder in the propagation process of the domain walls is observed. It is also found that the bubble configuration near the saturation field is unstable.

Nanoscale magneto-structural coupling in as-deposited and freestanding single-crystalline Fe7Pd3ferromagnetic shape memory alloy thin films

“…If the easy axis is oriented normal to the surface, magnetization slightly rotates out-of-plane and is detectable by MFM. Once the amount of this magnetocrystalline anisotropy increases, not only moment M z components and domain stripe widths/wall widths are affected [15] but also the order of the stripe pattern may transform to a maze structure or even toward unordered island-like domain configurations in the case of a dominating magnetocrystalline energy contribution [16]. This explanation leads to the discussion of finding (i).…”

Magnetization reversal in an obliquely oriented metal evaporated tape

“…4) shows proof that the reversal of magnetization takes place by a process, in which the film breaks in an incoherent collage of domains. We know the grains size has a lateral dimension of B150 ( A [6], and in other systems it was shown that magnetic domains and crystalline grains are indeed of the same size [23]. The spin averaged reflectivity R T (Fig.…”

Temperature and thickness dependence at the onset of perpendicular magnetic anisotropy inFePdthin films sputtered onMgO(001)

“…Regarding the growth of FePd directly on MgO͑001͒, molecular beam epitaxy ͑MBE͒ has been the most commonly used deposition technique. [16][17][18][19] For example, Kamp et al 19 studied the chemical ordering and morphology of FePd alloys deposited at temperatures ranging from room temperature ͑RT͒ up to 510°C, obtaining a maximum value of S = 0.91 at 350°C. A comparison between the structure and the magnetic properties of systems fabricated using different deposition techniques, such as MBE and sputtering, is of special interest for technological applications, considering that these two techniques involve different energies thus affecting the growth mode, and sputtering might be preferred for industrial fabrication of high anisotropy binary alloys for new storage media.…”