Lorentz microscopy and small-angle electron diffraction study of magnetic textures inLa1−xSrxMnO

Abstract

Magnetic textures in the ferromagnetic phases of La 1-xSrxMnO3 for 0.15 < x < 0.30 have been investigated by Lorentz microscopy combined with small-angle electron diffraction experiments. Various types of magnetic textures characterized by stripe, plate-shaped, and cylindrical (magnetic bubble) domains were found. Two distinct types of magnetic stripe domains appeared in the orthorhombic structure with an inversion symmetry of La0.825Sr0.175MnO3, depending significantly on magnet ocrystalline anisotropy. Based on in-situ observations as functions of temperature and the strength of the external magnetic field, a magnetic field-temperature phase diagram was constructed, showing the stabilization of magnetic bubbles in the ferromagnetic phase of La0.825Sr0.175MnO3. P.A.C. S numbers: 75.70Kw, 75.47.Lx, 75.78.Fq, 68.37.Lp

Crystal-orientation dependence of magnetic domain structures in the skyrmion-hosting magnets MnNiGa

“…We note that the changes in the magnetic domains from different crystal orientations are mainly caused by the magnetic anisotropy, which are in accordance with the magnetic structures reported in Ref. 23 by using small-angle electron diffraction (SmAED).…”

“…24 As one of the few bi-skyrmion-hosting centrosymmetric magnets, the magnetic anisotropy and variable spin structures have also been investigated in layered perovskite manganites. 22,23 In our previous work, we have identified an extremely stable magnetic biskyrmion state at room temperature in the nonchiral MnNiGa hexagonal magnet; 19 however, the effects of crystal orientation on the topological spin textures of the MnNiGa alloy have not been systematically investigated and fully understood yet. In this letter, we investigated the various topological spin textures of MnNiGa alloy with changing the crystal orientation by systematic real-space observations using Lorentz transmission electron microscopy.…”

“…Mori et al 22,23 have reported that the magnetic domain structures depended significantly on the relationship between the magnetic easy axis and the direction of the a Author to whom correspondence should be addressed: wenhong.wang@iphy.ac.cn applied magnetic field. They showed different spin textures with the magnetic field applying along various crystal orientations of the sample.…”

Stripe domains reorientation in ferromagnetic films with perpendicular magnetic anisotropy

“…Weak stripe domains were first predicted theoretically [32,33] and later discovered experimentally in NiFe films [19,34]. In the following years, the phenomenon has been found and deepened in different kinds of thin films with moderate PMA, such as FeGa [35][36][37][38], FeN [31,39,40], FeSiB [41,42], CoFeB [43], FeTaN [44], GdFe [45], NdCo [46], FeCoZr [23], La x Sr 1−x MnO 3 [47] and multilayers with moderate perpendicular anisotropy [48][49][50]. Very recently, it has been shown [51] that the formation of stripe domains can be induced in a Py film, even far below the critical thickness, by coupling the Py film to a NdCo one, characterized by a moderate PMA.…”

“…The subject is currently attracting wide interest, thanks to the central role played today by magnetic thin films with PMA in many applications, from memories to logic devices and sensors [52]. Current active research on PMA films and multilayers is focused onto the definition of magnetic phase diagrams into different systems where magnetic stripe and skyrmion or bubble phases compete [30,47,50,[53][54][55][56][57]. Nanoscale magnetic textures are today the focus of a wide area of research, thanks to the possibility of generating and controlling the propagation of domains, bubbles, skyrmions and other kinds of spin textures for realizing, e.g.…”