The material, constructed of two different compounds, might one day allow computers to use the magnetic spin of electrons, in addition to their charge, for computation. A host of innovations could result, including fast memory devices that use considerably less power than conventional systems and still retain data when the power is off.
The team's effort not only demonstrates that the custom-made material's properties can be engineered precisely, but in creating a virtually perfect sample of the material, the team also has revealed a fundamental characteristic of devices that can be made from it.
Team members from ANL began by doing something that had never been done before-engineering a highly ordered version of a magnetic oxide compound that naturally has two randomly distributed elements: lanthanum and strontium. Stronger magnetic properties are found in those places in the lattice where extra lanthanum atoms are added. Precise placement of the strontium and lanthanum within the lattice can enable understanding of what is needed to harness the interaction of the magnetic forces among the layers for memory storage applications, but such control has been elusive up to this point.
"These oxides are physically messy to work with, and until very recently, it was not possible to control the local atomic structure so precisely," says Brian Kirby, a physicist at the NIST Center for Neutron Research (NCNR). "Doing so gives us access to important fundamental properties, which are critical to understand if you really want to make optimal use of a material."
The team members from ANL have mastered a technique for laying down the oxides one atomic layer at a time, allowing them to construct an exceptionally organized lattice in which each layer contains only strontium or lanthanum, so that the interface between the two components could be studied. The NIST team members then used the NCNR's polarized neutron reflectometer to analyze how the magnetic properties within this oxide lattice changed as a consequence of the near-perfect placement of atoms.
They found that the influence of electrons near the additional lanthanum layers was spread out across three magnetic layers in either direction, but fell off sharply further away than that. Tiffany Santos, lead scientist on the study from ANL, says that the measurement will be important for the emerging field of oxide spintronics, as it reveals a fundamental size unit for electronic and magnetic effects in memory devices made from the material.
"For electrons to share spin information-something required in a memory system-they will need to be physically close enough to influence each other," Kirby says. "By ordering this material in such a precise way, we were able to see just how big that range of influence is."
* T. S. Santos, B. J. Kirby, S. Kumar, S. J. May, J. A. Borchers, B. B. Maranville, J. Zarestky, S. G. E. te Velthuis, J. van den Brink and A. Bhattacharya. Delta doping of ferromagnetism in antiferromagnetic manganite superlattices. Physical Review Letters, Week ending Oct. 14, 2011, 107, 167202 (2011), DOI: 10.1103/PhysRevLett.107.167202.
Chad Boutin | EurekAlert!
First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester
Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy