New Method Enables High-Resolution Measurements of Magnetism

In a new article, published in Nature Materials, researchers from Beijing, Uppsala and Jülich have made significant progress allowing very high resolution magnetic measurements. With their method it is possible to measure magnetism of individual atomic planes.

sperm, brain tumours, Common drugs, diabetes, chronic wounds, magnetism, intestinal tumours, molecular scissors, disease, genetic, immune cells, drug development, Diabetes, Antibiotic, hydrogen generation, chronic obstructive pulmonary disease, malaria, photosynthesis, kidney failure, Brain tumours, mental health, blood cancer, cancer, dementia, cancer treatment, antibiotic resistance, blood vessel leakage, quantum simulations, atrial fibrillation, batteries, goiter treatment, terahertz radiation, organic materials , Guild of European Research Intensive Universities, gene copies, social anxiety, blue light screens, ‘Our hope is that these findings will make it possible to discover a way to selectively inhibit the TGF-beta signals that stimulate tumour development without knocking out the signals that inhibit tumour development, and that this can eventually be used in the fight against cancer,’ says Eleftheria Vasilaki, postdoctoral researcher at Ludwig Institute for Cancer Research at Uppsala University and lead author of the study. TGF-beta regulates cell growth and specialisation, in particular during foetal development. In the context of tumour development, TGF-beta has a complicated role. Initially, it inhibits tumour formation because it inhibits cell division and stimulates cell death. At a late stage of tumour development, however, TGF-beta stimulates proliferation and metastasis of tumour cells and thereby accelerates tumour formation. TGF-beta’s signalling mechanisms and role in tumour development have been studied at the Ludwig Institute for Cancer Research at Uppsala University for the past 30 years. Recent discoveries at the Institute, now published in the current study in Science Signaling, explain part of the mechanism by which TGF-beta switches from suppressing to enhancing tumour development. Uppsala researchers, in collaboration with a Japanese research team, discovered that TGF-beta along with the oncoprotein Ras, which is often activated in tumours, affects members of the p53 family. The p53 protein plays a key role in regulating tumour development and is often altered – mutated – in tumours. TGF-beta and Ras suppress the effect of mutated p53, thereby enhancing the effect of another member of the p53 family, namely delta-Np63, which in turn stimulates tumour development and metastasis.

Magnetic nanostructures are used in a wide range of applications. Most notably, to store bits of data in hard drives. These structures are becoming so small that the usual magnetic measurement methods fail to provide data with sufficient resolution.

Due to the ever-growing demand for more powerful electronic devices, the next generation spintronic components must have functional units that are only a few nanometers large. It is easier to build a new spintronic device, if we can see it in sufficient detail. This is becoming increasingly difficult with the rapid advance of nanotechnologies. One instrument capable of such detailed imaging is the transmission electron microscope.

An electron microscope is a unique experimental tool offering scientists and engineers a wealth of information about all kinds of materials. As opposed to optical microscopes, it uses electrons to study the materials. This enables enormous magnifications. For example, in crystals one can routinely observe individual columns of atoms. Electron microscopes provide information about structure, composition and chemistry of materials. Recently, researchers also found ways to use electron microscopes to measure magnetic properties. However, atomic resolution has not yet been reached in this application.

Ján Rusz and Dmitry Tyutyunnikov at Uppsala University, together with colleagues from Tsinghua University, China, and Forschungszentrum Jülich in Germany have developed and experimentally proven a new method that allows magnetic measurements of individual atomic planes. The method uses a unique transmission electron microscope PICO that can correct both geometrical and chromatic aberrations, allowing a detailed look at individual atomic planes over a wide spectral range.

“The idea came from Dr. Xiaoyan Zhong, with whom we have a growing fruitful collaboration. We have contributed simulations, which have confirmed the validity of the experimental design and demonstrated that the experiment really offers a very detailed look at magnetism of materials,” says Ján Rusz.

Source : Uppsala University