Magnetic force microscopy of epitaxial magnetite films through the Verwey transition

Lee, A. K. H.; Jayathilaka, Priyanga; Bauer, C. A.; Monti, Mark C.; Markert, J. T.; Lozanne, Alex de; Miller, Casey W.

doi:10.1063/1.3502606

Cited by 9 publications

(4 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This reduced strain appears to reduce the density of antiphase boundaries, as inferred from mobile magnetic domains observed with temperaturedependent MFM. This is in contrast to magnetite grown directly on MgO [18].…”

Section: Impact Of Thin Buffer Layers On Magnetitecontrasting

confidence: 57%

Heterostructures for Realizing Magnon-Induced Spin Transfer Torque

Jayathilaka

Monti

Markert

et al. 2012

Advances in Condensed Matter Physics

Self Cite

View full text Add to dashboard Cite

This work reports efforts fabricating heterostructures of different materials relevant for the realization of magnon-induced spin transfer torques. We find the growth of high-quality magnetite on MgO substrates to be straightforward, while using transition metal buffer layers of Fe, Cr, Mo, and Nb can alter the structural and magnetic properties of the magnetite. Additionally, we successfully fabricated and characterized Py/Cr/Fe3O4and Fe3O4/Cr/Fe3O4spin valve structures. For both, we observe a relatively small giant magnetoresistance and confirm an inverse dependence on spacer layer thickness. Thus, we have shown certain materials combinations that may form the heterostructures that are the building blocks necessary to achieve magnon-induced spin transfer torque devices.

show abstract

Section: Impact Of Thin Buffer Layers On Magnetitecontrasting

confidence: 57%

Heterostructures for Realizing Magnon-Induced Spin Transfer Torque

Jayathilaka

Monti

Markert

et al. 2012

Advances in Condensed Matter Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…These antiferromagnetic spins close to an APB lay out-ofplane, overwhelming the shape anisotropy and forming a narrow magnetic domain wall under application of an external field [133]. As the magnetic domain sizes are at least 2-4 times larger than the structural APDs, the APBs pin the magnetic domains even across the magnetic reorientation occuring close to the VT [145,146]. The pinned magnetic domain walls contribute positively to the MR for fields below the magnetocrystalline anisotropy field, which has allowed its measurement above T V at Fe 3 O 4 (1 1 0) films on MgO substrates [94].…”

Section: Antiphase Domain Boundariesmentioning

confidence: 99%

Electronic phase transitions in ultrathin magnetite films

Bernal-Villamil

Gallego

2015

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Magnetite (Fe3O4) shows singular electronic and magnetic properties, resulting from complex electron-electron and electron-phonon interactions that involve the interplay of charge, orbital and spin degrees of freedom. The Verwey transition is a manifestation of these interactions, with a puzzling connection between the low temperature charge ordered state and the dynamic charge fluctuations still present above the transition temperature. Here we explore how these rich physical phenomena are affected by thin film geometries, particularly focusing on the ultimate size limit defined by thicknesses below the minimum bulk unit cell. On one hand, we address the influence of extended defects, such as surfaces or antiphase domains, on the novel features exhibited by thin films. On the other, we try to isolate the effect of the reduced thickness on the electronic and magnetic properties. We will show that a distinct phase diagram and novel charge distributions emerge under reduced dimensions, while holding the local high magnetic moments. Altogether, thin film geometries offer unique possibilities to understand the complex interplay of short- and long-range orders in the Verwey transition. Furthermore, they arise as interesting candidates for the exploitation of the rich physics of magnetite in devices that demand nanoscale geometries, additionally offering novel functionalities based on their distinct properties with respect to the bulk form.

show abstract

“…Further evidence of U moment ordering can be obtained from the frequency shift as a function of temperature, which is approximately proportional to the second derivative of magnetization. Indeed, the frequency shift in an MFM image can be used as a qualitative measure of the local magnetization [20]. We perform a zero-field cooling experiment and focus on a relatively small area to avoid long scanning times, and the region is labeled in Fig.…”

Section: Resultsmentioning

confidence: 99%

Imaging the magnetic states in an actinide ferromagnet UMn2Ge2

Tan

Berg

Lozanne

et al. 2018

Phys. Rev. Materials

View full text Add to dashboard Cite

We present studies of the magnetic domain structure of UMn2Ge2 single crystals using a homebuilt low temperature magnetic force microscope. The material has two distinct magnetic ordering temperatures, originating from the Mn and U moments. At room temperature, where the Mn moments dominate, there are flower-like domain patterns similar to those observed in uniaxial ferromagnets. After exposing the sample to a one-tesla magnetic field near 40 K, the evolution of the magnetic domains are imaged through zero-field warming up to 210 K. Near the ordering temperature of the Uranium moments a clear change in the domain wall motion is observed. The domain size analysis of the flower-like pattern reveals that the domain structure is consistent with a model of branching domains. PACS numbers: May be entered using the \pacs{#1} command.

show abstract

Magnetic force microscopy of epitaxial magnetite films through the Verwey transition

Cited by 9 publications

References 23 publications

Heterostructures for Realizing Magnon-Induced Spin Transfer Torque

Heterostructures for Realizing Magnon-Induced Spin Transfer Torque

Electronic phase transitions in ultrathin magnetite films

Imaging the magnetic states in an actinide ferromagnet UMn2Ge2

Contact Info

Product

Resources

About