Mobile Cylindrical Magnetic Domains in Epitaxial Garnet Films

Abstract

The properties of cylindrical domains in wafers of bulk single crystals of various magnetic oxides have been extensively studied and described in recent months. Mobile cylindrical domains have been produced in single-crystal thin films of gallium-substituted yttrium iron garnet. The deposits are formed by chemical vapor deposition onto nonmagnetic garnet substrates greater than 1 cm2 in area. A model of magnetic anisotropy in epitaxial films is proposed and shown to be in good agreement with experimental domain observations. In a typical sample, a domain diameter of 8 μ is observed in a 6-μ-thick film at a bias field of 25 Oe. From the domain translational velocity of 5600 cm/sec, a cylindrical domain mobility of 1500 cm/sec Oe has been calculated. A fractional change in cylindrical domain diameter of −0.07%/°K has been measured at 300°K. Annealing at 1570°K for several hours did not alter the Néel temperature or the optical transmission spectrum.

Strain-induced perpendicular magnetic anisotropy and Gilbert damping of Tm3Fe5O12 thin films

“…According to refs. 10,11 , iron garnets with a negative (positive) magnetostriction constant ( λ 111 ) can have an out-of-plane (oop) easy axis of magnetization when grown under in-plane tensile (compressive) strain. Several approaches have been proposed to achieve for YIG layers an oop easy axis of magnetization, including the variation of oxygen pressure during growth and substrate type 12 .…”

Anomalous Hall hysteresis inTm3Fe5O12/Ptwith strain-induc

“…When the surface anisotropy is sufficiently strong to overcome the shape anisotropy, a squared hysteresis loop is resulted 20 . Along the <111> orientation of cubic crystals 21 ,…”

“…When the surface anisotropy is sufficiently strong to overcome the shape anisotropy, a squared hysteresis loop is resulted 22 . Along the <111> orientation of cubic crystals 23 , || , where K 1 , λ 111 , σ || , and M s stand for the 1st-order cubic anisotropy, magnetostriction constant, in-plane stress, and saturation magnetization of the film, respectively. TIG, as a member of the rare earth iron garnet family, has a large negative magnetostriction constant (λ 111 = -5.2) 24 , about twice as much as that of YIG (λ 111 = -2.7) 24 .…”

An integrated approach to doped thin films with strain-tunable magnetic anisotropy: powder synthesis, target preparation and pulsed laser deposition of Bi:YIG

“…In YIG thin films grown on YAG substrate, magnetic anisotropy Ku is dominated by the shape anisotropy, resulting in the easy axis directed in-plane, as seen in the inset of Fig 4a. One could tune the magnetic anisotropy by introducing lattice constant mismatch induced magnetostriction. [15,25] Along the <111> orientation of cubic crystals, the magnetostriction effect induced effective perpendicular anisotropy field is described as H ⊥ ~− 3 111 || , [26] where the λ111, σ||, and Ms are the magnetostriction constant, in-plane stress, and saturation magnetization, respectively. The negative value of λ111 (-4.45 × 10 -6 ) in garnet films requires a tensile stress (σ|| > 0) in order to produce a positive perpendicular anisotropy field, needed for PMA.…”