Influence of magnetic domain walls on all-optical magnetic toggle switching in a ferrimagnetic GdFe film

• Rahil Hosseinifar,
• Evangelos Golias,
• Ivar Kumberg,
• Quentin Guillet,
• Karl Frischmuth,
• Sangeeta Thakur,
• Mario Fix,
• Manfred Albrecht,
• Florian Kronast and
• Wolfgang Kuch

Beilstein J. Nanotechnol. 2022, 13, 74–81, doi:10.3762/bjnano.13.5

• dichroism (XMCD) as magnetic contrast mechanism. We focus single ultrashort infrared laser pulses of 100 fs temporal width to the vicinity of magnetic domain walls and study the local deviations from a perfect, deterministic toggle switching and their relation to the domain-wall position for temperatures

• patterns, recorded in static XMCD-PEEM imaging before and after excitation of the sample by a single laser pulse in absence of any magnetic field reveals the lateral distribution of optically switched areas. Figure 1 presents an example. Figure 1a and Figure 1b show the domain structure before and after

• presents XMCD-PEEM images of a magnetic domain that has been positioned completely within the threshold line for toggle switching. Figure 3A shows the starting configuration, Figure 3B the result after three laser pulses with incident fluence of 7.9 mJ/cm2 in the center. Here the sample is at a temperature

Size limits of magnetic-domain engineering in continuous in-plane exchange-bias prototype films

• Alexander Gaul,
• Daniel Emmrich,
• Timo Ueltzhöffer,
• Henning Huckfeldt,
• Hatice Doğanay,
• Johanna Hackl,
• Muhammad Imtiaz Khan,
• Daniel M. Gottlob,
• Gregor Hartmann,
• André Beyer,
• Dennis Holzinger,
• Slavomír Nemšák,
• Claus M. Schneider,
• Armin Gölzhäuser,
• Günter Reiss and
• Arno Ehresmann

Beilstein J. Nanotechnol. 2018, 9, 2968–2979, doi:10.3762/bjnano.9.276

• stripe domains [43]. To complement the MFM data, X-PEEM measurements have been performed to analyze the local magnetization states by X-ray magnetic circular dichroism (XMCD) measurements. Two different sensitivity directions have been chosen: Figure 2a–c shows the results when the projection of the

• prevailing yellow DW contrast. This is in accordance with the XMCD data in Figure 2, where the misalignment of the adjacent unidirectional anisotropy axes promoted unwinding DWs. The corresponding charges are compensated by opposite magnetization areas in the top-left and bottom-right corners (blue areas

• imaged with a 43 μm field of view. One image pixel represents a sample area of 65 nm × 65 nm. Of particular note is that the XMCD signal Δ of the partial electron yield of the two respective helicities (Δ = (Iσ+ − Iσ−)/(Iσ+ + Iσ−)) is proportional to . Micromagnetic simulations Micromagnetic simulations

Cubic chemically ordered FeRh and FeCo nanomagnets prepared by mass-selected low-energy cluster-beam deposition: a comparative study

• Veronique Dupuis,
• Anthony Robert,
• Arnaud Hillion,
• Ghassan Khadra,
• Nils Blanc,
• Damien Le Roy,
• Florent Tournus,
• Clement Albin,
• Olivier Boisron and
• Alexandre Tamion

Beilstein J. Nanotechnol. 2016, 7, 1850–1860, doi:10.3762/bjnano.7.177

• using various experimental techniques [4]. Here, we focus on anomalous X-rays diffraction (AXD) and X-ray magnetic circular dichroism (XMCD) performed by using well-adapted synchrotron radiation beamlines. We show how the competition between the stable bimetallic NPs structure and their chemical

• magnetic characteristic parameters such as the magnetic particle diameter Dm identical to that of the TEM distribution and the normal evolution of the Keff distribution upon annealing. In order to obtain the atomic magnetic moments and to correlate them to the finite-size effect in nanoalloys, we use XMCD

• magnetic moments measured from XMCD are reached by using the sum rules [28][29]. Discussion At first, it is to notice that FeRh and FeCo samples are all ferromagnetic at low temperatures. In contrast to the anti-ferromagnetic order expected for the B2 phase in the bulk FeRh phase diagram (Figure 1a), we

Magnetic switching of nanoscale antidot lattices

• Ulf Wiedwald,
• Joachim Gräfe,
• Kristof M. Lebecki,
• Maxim Skripnik,
• Felix Haering,
• Gisela Schütz,
• Paul Ziemann,
• Eberhard Goering and
• Ulrich Nowak

Beilstein J. Nanotechnol. 2016, 7, 733–750, doi:10.3762/bjnano.7.65

Effects of spin–orbit coupling and many-body correlations in STM transport through copper phthalocyanine

• Benjamin Siegert,
• Andrea Donarini and
• Milena Grifoni

Beilstein J. Nanotechnol. 2015, 6, 2452–2462, doi:10.3762/bjnano.6.254

• of metallorganic compounds, such as the widely studied metal phthalocyanines [7][8], exhibit sizeable magnetic anisotropy induced by the interplay of electronic correlations and SOI. Indeed, in an X-ray magnetic circular dichroism (XMCD) analysis copper phthalocyanine (CuPc) was found to exhibit

Magnetic properties of self-organized Co dimer nanolines on Si/Ag(110)

• Lisa Michez,
• Kai Chen,
• Fabien Cheynis,
• Frédéric Leroy,
• Alain Ranguis,
• Haik Jamgotchian,
• Margrit Hanbücken and
• Laurence Masson

Beilstein J. Nanotechnol. 2015, 6, 777–784, doi:10.3762/bjnano.6.80

• magnetic circular dichroism (XMCD); Introduction In the last fifteen years, bottom-up approaches have provided promising routes for creating a wide range of nanostructures with new magnetic, electronic, photonic or catalytic properties. Such approaches are based on growth phenomena after atoms and

• , Co nanolines. The first magnetic characterization results of the Co nanolines using X-ray magnetic circular dichroism (XMCD) are reported, revealing that the atomic Co layer directly adsorbed onto the Si nanoribbons presents a weak magnetic response. The second Co layer exhibits an enhanced

• only few, bare silver areas remain, suggesting that the process of Co incorporation into the Si NRs is efficiently blocked at this temperature. In the following section, magnetic characterization of such assemblies of Co nanolines using XMCD is reported. Magnetic characterization of the Co dimer

UHV deposition and characterization of a mononuclear iron(III) β-diketonate complex on Au(111)

• Irene Cimatti,
• Silviya Ninova,
• Valeria Lanzilotto,
• Luigi Malavolti,
• Luca Rigamonti,
• Brunetto Cortigiani,
• Matteo Mannini,
• Elena Magnano,
• Federica Bondino,
• Federico Totti,
• Andrea Cornia and
• Roberta Sessoli

Beilstein J. Nanotechnol. 2014, 5, 2139–2148, doi:10.3762/bjnano.5.223

• fragmentation of Fe(dpm)3 upon adsorption on the Au(111) surface. Structural features with intact molecules were only observed for the saturation coverage. An ex situ prepared thick film of the complex was also investigated by X-ray magnetic circular dichroism (XMCD) and features typical of high-spin iron(III

• ) in octahedral environment were observed. Keywords: Au(111); β-diketonate complexes; DFT; STM; thin films; UPS; XMCD; XPS; Introduction A renewed interest in mononuclear metal complexes has recently arisen due to the observation that systems of this class can behave as single molecule magnets (SMMs

• (bipy) on Au(111) [34], where 20% of the molecules are able to preserve the SCO behavior. XMCD of a Fe(dpm)3 thick film Given the interest in Fe(dpm)3 as a potential contaminant of evaporable Fe4 SMMs [12], the magnetic characterization of an ex situ preparation was also attempted. Considering that the

Cathode lens spectromicroscopy: methodology and applications

• T. O. Menteş,
• G. Zamborlini,
• A. Sala and
• A. Locatelli

Beilstein J. Nanotechnol. 2014, 5, 1873–1886, doi:10.3762/bjnano.5.198

• and combine chemical characterization with X-ray magnetic circular dichroism–photoemission electron microscopy (XMCD–PEEM) magnetic imaging by using the variable photon polarization and energy available at the synchrotron source. Keywords: gold (Au); graphene; intercalation; low-energy electron

• microscopy (LEEM); magnetism; nanostructures; X-ray magnetic circular dichroism (XMCD); X-ray photoemission electron microscopy (XPEEM); Introduction The cathode lens, or immersion objective lens, is used to image electrons emitted from surfaces [1]. In a microscope that uses this type of objective, the

• known to carry a contribution from magnetization, which is greatly enhanced at energies corresponding to certain absorption thresholds [19]. Therefore, XPEEM images can be used to obtain the magnetization distribution on a magnetic surface by a simple polarization analysis [20]. The XMCD-PEEM imaging is

Antiferromagnetic coupling of TbPc₂ molecules to ultrathin Ni and Co films

• David Klar,
• Svetlana Klyatskaya,
• Andrea Candini,
• Bernhard Krumme,
• Kurt Kummer,
• Philippe Ohresser,
• Valdis Corradini,
• Valentina de Renzi,
• Roberto Biagi,
• Loic Joly,
• Jean-Paul Kappler,
• Umberto del Pennino,
• Marco Affronte,
• Heiko Wende and
• Mario Ruben

Beilstein J. Nanotechnol. 2013, 4, 320–324, doi:10.3762/bjnano.4.36

• corresponding circular or linear dichroism at the Tb M4,5 absorption edges of TbPc2 on Cu(100). The XMCD signal has the shape typical for a Tb3+ ion, in agreement with what has been already reported for this molecule [20][21][24][25]. The high XMCD intensity at the M5 edge and the low intensity at the M4 edge

• magnetization perpendicular to the phthalocyanine plane [21]. Thus, the easy axis of the molecules is parallel to the one of the underlying Ni film. From the field-dependent XMCD at both Tb M5 and Ni L3 absorption edges presented in Figure 3, the influence of the Ni film on the magnetization of the molecules is

• XMCD study together with comparison to ab initio calculations, e.g., by utilizing density functional theory (DFT). Magnetic coupling on a Co substrate The important difference between the Co and the Ni substrate is the orientation of the magnetic easy axis that is parallel to the surface for the 10 ML

Physics, chemistry and biology of functional nanostructures

• Paul Ziemann and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2012, 3, 843–845, doi:10.3762/bjnano.3.94

• facilities has made an important contribution, now providing beams with spot sizes even below 10 nm, thus promising the application of spectroscopies such as photoelectron emission microscopy (PEEM) or X-ray magnetic circular dichroism (XMCD) on a single nanoobject [6][7]. Progress in the theoretical

Tuning the properties of magnetic thin films by interaction with periodic nanostructures

• Ulf Wiedwald,
• Felix Haering,
• Stefan Nau,
• Carsten Schulze,
• Herbert Schletter,
• Denys Makarov,
• Alfred Plettl,
• Karsten Kuepper,
• Manfred Albrecht,
• Johannes Boneberg and
• Paul Ziemann

Beilstein J. Nanotechnol. 2012, 3, 831–842, doi:10.3762/bjnano.3.93

• transmission X-ray microscopy images of Fe films taken with right circularly polarized light at the Fe-L3 edge show PS particles as well as magnetic contrast in the film after sample demagnetization. Panel (b) presents the XMCD image of the identical sample spot. In (c) an XMCD image at higher resolution is

Nanoscaled alloy formation from self-assembled elemental Co nanoparticles on top of Pt films

• Luyang Han,
• Ulf Wiedwald,
• Johannes Biskupek,
• Kai Fauth,
• Ute Kaiser and
• Paul Ziemann

Beilstein J. Nanotechnol. 2011, 2, 473–485, doi:10.3762/bjnano.2.51

• ; nanoparticles; Pt; XMCD; Introduction Magnetic nanoparticles (NPs), with narrow distributions of their size and mutual spacing, offer a high potential with respect to both, fundamental and applied studies [1][2][3][4]. Although a broad palette of methods has been established for the preparation of such NPs, if

• alloy formation by X-ray absorption spectroscopy and SQUID magnetometry. The excellent sensitivity of SQUID magnetometers can be exploited, at suitably selected temperatures, to detect the magnetic response corresponding to the Co particles and nanoscale alloys. X-ray magnetic circular dichroism (XMCD

• ) derives its sensitivity from being both element specific and surface sensitive. It is therefore ideally suited for the kind of specimens studied here. In addition to the information contained in (both, SQUID and XMCD) hysteresis loops, we obtain spectroscopic signatures of the average magnetocrystalline

Extended X-ray absorption fine structure of bimetallic nanoparticles

• Carolin Antoniak

Beilstein J. Nanotechnol. 2011, 2, 237–251, doi:10.3762/bjnano.2.28

• ], X-ray magnetic linear dichroism (XMLD) [24][25], X-ray magnetic circular dichroism (XMCD) [26][27], and the more exotic X-ray non-reciprocal linear dichroism [28] and magnetochiral dichroism (XMχD) [29]. In a microscopic picture, this dependence of the absorption on the polarisation of incident X

• influence of the chemical environment on the magnetic moments of the Fe atoms in FexPt1−x bulk materials have been investigated by XMCD analysis and spin polarised relativistic Korringa–Kohn–Rostoker (SPR-KKR) calculations [54][91]: The higher the Fe content in the alloy, the smaller the spin magnetic

• detailed study of the (local) structure for data interpretation in terms of magnetic or electronic characterisation was discussed on the basis of magnetic moments of FexPt1−x alloys measured by XMCD [68] and calculated using the SPR-KKR method. In summary, the different aspects of X-ray absorption

Structural and magnetic properties of ternary Fe_1–xMn_xPt nanoalloys from first principles

• Markus E. Gruner and
• Peter Entel

Beilstein J. Nanotechnol. 2011, 2, 162–172, doi:10.3762/bjnano.2.20

• film setup. Using a vibrating sample magnetometer for saturation magnetization and hysteresis loop and X-ray magnetic circular dichroism (XMCD) to obtain the element resolved orientation of the moments, the authors observed a linear decrease of the average magnetization with increasing Mn-content

• , which finally vanishes completely around x = 0.5. From their XMCD data, the authors conclude that Mn and Fe predominately align in an antiparallel fashion over the whole composition range and thus rule out a composition-dependent sign change in the Fe–Mn magnetic exchange constant which was postulated

Structure, morphology, and magnetic properties of Fe nanoparticles deposited onto single-crystalline surfaces

• Armin Kleibert,
• Wolfgang Rosellen,
• Mathias Getzlaff and
• Joachim Bansmann

Beilstein J. Nanotechnol. 2011, 2, 47–56, doi:10.3762/bjnano.2.6

• combined approach of X-ray magnetic circular dichroism (XMCD), reflection high energy electron diffraction (RHEED) and scanning tunneling microscopy (STM) to shed light on the complex and size-dependent relation between magnetic properties, crystallographic structure, orientation and morphology. In

• particular XMCD reveals that Fe particles on Ni(111)/W(110) have a significantly lower (higher) magnetic spin (orbital) moment compared to bulk iron. The reduced spin moments are attributed to the random particle orientation being confirmed by RHEED together with a competition of magnetic exchange energy at

• process might be accompanied by a complex reshaping of the particles. Keywords: epitaxy; iron; magnetic nanoparticles; Ni(111); RHEED; spontaneous self-alignment; STM; W(110); XMCD; Introduction Ferromagnetic clusters and nanoparticles have gained huge interest due to their interesting fundamental

Ultrafine metallic Fe nanoparticles: synthesis, structure and magnetism

• Olivier Margeat,
• Marc Respaud,
• Catherine Amiens,
• Pierre Lecante and
• Bruno Chaudret

Beilstein J. Nanotechnol. 2010, 1, 108–118, doi:10.3762/bjnano.1.13

• α-Fe NPs with diameters down to 2 nm show an enhancement of the hyperfine field BHyp, indicative of enhanced µFe [10][11][12]. Recent careful measurements, by X-ray magnetic circular dichroism (XMCD) [13][14][15][16], consistently indicate an increase in the ratio of the orbital magnetic moment over

• restricted to free clusters and therefore cannot explain all these experimental results. Calculations of the orbital contribution lead to an enhanced µL/µS ratio compared to the bulk value, but this enhancement is smaller than those estimated from XMCD measurements [9]. Interestingly, calculations by Pastor

• moments are estimated to be 2.46 µB and 0.13 µB, respectively. This demonstrates that the enhancement of the total magnetic moment has contributions from both µL and µS. In comparison to the estimations made on other systems using XMCD [13][14][15][16], the average total magnetic moment per Fe atom is of

Preparation and characterization of supported magnetic nanoparticles prepared by reverse micelles

• Ulf Wiedwald,
• Luyang Han,
• Johannes Biskupek,
• Ute Kaiser and
• Paul Ziemann

Beilstein J. Nanotechnol. 2010, 1, 24–47, doi:10.3762/bjnano.1.5

• magnetic circular dichroism (XMCD) which provides information on (i) the chemical state of sample, (ii) element-specific magnetic moments and (iii) element-specific hysteresis loops. The results presented below were measured at beamline PM-3 of the BESSY II synchrotron facility in Berlin, Germany. The

• the XMCD and hysteresis loops were always measured in out-of-plane geometry. Moreover, our home-built plasma etching system can be attached to the high-field end-station which allows full in situ sample manipulation and characterization [32]. 3.3.1 Tracking the phase transition in FePt nanoparticles