Tag Archives: PPP-MFMR

Observation of a gel of quantum vortices in a superconductor at very low magnetic fields

A gel consists of a network of particles or molecules formed for example using the sol-gel process, by which a solution transforms into a porous solid. Particles or molecules in a gel are mainly organized on a scaffold that makes up a porous system. Quantized vortices in type-II superconductors mostly form spatially homogeneous ordered or amorphous solids.*

In the article “Observation of a gel of quantum vortices in a superconductor at very low magnetic fields” José Benito Llorens, Lior Embon, Alexandre Correa, Jesús David González, Edwin Herrera, Isabel Guillamón, Roberto F. Luccas, Jon Azpeitia, Federico J. Mompeán, Mar García-Hernández, Carmen Munuera, Jazmín Aragón Sánchez, Yanina Fasano, Milorad V. Milošević, Hermann Suderow and Yonathan Anahory present high-resolution imaging of the vortex lattice displaying dense vortex clusters separated by sparse or entirely vortex-free regions in β−Bi2Pd superconductor.*

The authors find that the intervortex distance diverges upon decreasing the magnetic field and that vortex lattice images follow a multifractal behavior. These properties, characteristic of gels, establish the presence of a novel vortex distribution, distinctly different from the well-studied disordered and glassy phases observed in high-temperature and conventional superconductors.*

The observed behavior is caused by a scaffold of one-dimensional structural defects with enhanced stress close to the defects. The vortex gel might often occur in type-II superconductors at low magnetic fields. Such vortex distributions should allow to considerably simplify control over vortex positions and manipulation of quantum vortex states.*

The results presented in the article show that vortices are nearly independent to each other at very low magnetic fields and that their position is locked to the defect structure in the sample. This suggests that vortices in this field range are also highly manipulable, much more than in usual hexagonal or disordered vortex lattices.

The magnetic force microscopy (MFM) measurements described in the article were performed in a commercial Low-Temperature  SPM equipment working in the 300–1.8  K temperature range using NANOSENSORS magnetic AFM probes of the type PPP-MFMR that were magnetized prior to the measurement by applying a magnetic field of 1500 G at 10 K.

figure 8 from “Observation of a gel of quantum vortices in a superconductor at very low magnetic fields” by José Benito Llorens et al.:
Behavior of the hexagonal vortex lattice as a function of temperature measured with MFM. In (a)–(c), the images are taken at 2.75,3.75, and 4.5 K, respectively at 300 G. The color scale represents the observed frequency shift. Scale bar is 1μm. Blue lines are the Delaunay triangulation of vortex positions. Blue and red points in (a) highlight vortices with seven and five nearest neighbors respectively. The dark arrow at the bottom highlights the position of the vertical line discussed in the text.
figure 8 from “Observation of a gel of quantum vortices in a superconductor at very low magnetic fields” by José Benito Llorens et al.:
Behavior of the hexagonal vortex lattice as a function of temperature measured with MFM. In (a)–(c), the images are taken at 2.75,3.75, and 4.5 K, respectively at 300 G. The color scale represents the observed frequency shift. Scale bar is 1μm. Blue lines are the Delaunay triangulation of vortex positions. Blue and red points in (a) highlight vortices with seven and five nearest neighbors respectively. The dark arrow at the bottom highlights the position of the vertical line discussed in the text.

*José Benito Llorens, Lior Embon, Alexandre Correa, Jesús David González, Edwin Herrera, Isabel Guillamón, Roberto F. Luccas, Jon Azpeitia, Federico J. Mompeán, Mar García-Hernández, Carmen Munuera, Jazmín Aragón Sánchez, Yanina Fasano, Milorad V. Milošević, Hermann Suderow, and Yonathan Anahory
Observation of a gel of quantum vortices in a superconductor at very low magnetic fields
Physical Review Research 2, 013329 (2020)
DOI:10.1103/PhysRevResearch.2.013329

Please follow this external link to read the full article: https://journals.aps.org/prresearch/pdf/10.1103/PhysRevResearch.2.013329

Open Access: The article “Observation of a gel of quantum vortices in a superconductor at very low magnetic fields” by José Benito Llorens, Lior Embon, Alexandre Correa, Jesús David González, Edwin Herrera, Isabel Guillamón, Roberto F. Luccas, Jon Azpeitia, Federico J. Mompeán, Mar García-Hernández, Carmen Munuera, Jazmín Aragón Sánchez, Yanina Fasano, Milorad V. Milošević, Hermann Suderow, and Yonathan Anahory is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation

Bone is the second most commonly transplanted tissue, preceded only by blood transfusion.Within this context, it is imperative to achieve the functional and structural restoration of damaged bone tissue. A major difficulty in bone tissue engineering arises from the fact that the bone regeneration process requires a long time for achieving a completely functional tissue. Generally, cells are seeded ex vivo into a three-dimensional (3D) biocompatible and sometimes biodegradable structure called scaffold, where they attach and grow. After the implantation into the injured site, the scaffolds should allow proper host cell colonization for regeneration purposes.*

Magnetic scaffolds emerged as promising solution for this purpose. Activation of the magnetic scaffolds using external static magnetic fields (SMF) prevents the decrease of bone mineral density and promotes the bone regeneration in bone fractures. The significant alterations in cell behaviors stimulated by the externally applied magnetic fields has been demonstrated in numerous studies. For example, it has been shown that an externally applied SMF using a magnet accelerates the osteogenic differentiation of osteoblasts-like cells in vitro and triggers peri-implant bone formation in vivo.*

The magnetism can also be used through scaffolding materials with magnetic properties. For example, biomaterials that incorporate magnetic nanoparticles (MNPs) are being developed.*

In the article «3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation” Irina Alexandra Paun, Bogdan Stefanita Calin, Cosmin Catalin Mustaciosu, Mona Mihailescu, Antoniu Moldovan, Ovidiu Crisan, Aurel Leca and Catalin Romeo Luculescu report on three-dimensional (3D) superparamagnetic scaffolds that enhanced the mineralization of magnetic nanoparticle-free osteoblast cells. The scaffolds were fabricated with submicronic resolution by laser direct writing via two photons polymerization of Ormocore/magnetic nanoparticles (MNPs) composites and possessed complex and reproducible architectures.*

To prove the magnetic nature of the MNPs in the polymerized composites, magnetic force microscopy (MFM) was carried out on scaffolds with different MNPs concentrations. NANOSENSORS™ PointProbe® Plus PPP-MFMR AFM probes with magnetic coating were used.*

Figure 5 from “3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation” by Irina Alexandra Paun et al:
Topographical (upper panel) and magnetic force microscopy (lower panel) images of scaffolds with MNPs concentrations of: (a,d) 0 mg/mL; (b,e) 2 mg/mL; (c,f) 4 mg/mL.

*Irina Alexandra Paun, Bogdan Stefanita Calin, Cosmin Catalin Mustaciosu, Mona Mihailescu, Antoniu Moldovan, Ovidiu Crisan, Aurel Leca and Catalin Romeo Luculescu
3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation
Materials 2019, 12(17), 2834
DOI: https://doi.org/10.3390/ma12172834

Please follow this link to read the full article: https://www.mdpi.com/1996-1944/12/17/2834/htm

Open Access The article “3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation” by Irina Alexandra Paun, Bogdan Stefanita Calin, Cosmin Catalin Mustaciosu, Mona Mihailescu, Antoniu Moldovan, Ovidiu Crisan, Aurel Leca and Catalin Romeo Luculescu is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.