Recent Developments in Science and Technology

Carbon Shows Magnetism at Room Temperature

Metal-free organic magnets were first discovered 10 years ago, but their magnetic properties were disappearing at temperatures only slightly above absolute zero. Now in a discovery made quite by accident, researchers have found the first example of an organic magnet that perseveres at higher temperatures.

Tatiana Makarova of the Ioffe Physico-Technical Institute in Russia and colleagues were searching for superconductivity in a polymer of fullerenea cage-like molecule comprised of 60 carbon atomsthey realized that their product demonstrated magnetic qualities at room temperature. The magnetization in some of the samples, the scientists write, was strong enough for them to be lifted off a table surface by a small magnet. The researchers suggest that the high-pressure, high-temperature processes required to create the polymer form of C60 results in a magnetically ordered state, although they are not sure exactly how this happens.

Attempts are going on in the direction to find out the reasons and it is sure that the result will represent a break through in the magnetism of metal free materials.

Researchers Create Nonmagnetic Magnet

Magnets, by definition, produce magnetic fields, but it is not necessarily, says a team of Japanese physicists in the September 17th issue of Physical Review Letters. Hiromichi Adachi of High Energy Accelerator Research Organization in Tsukuba, Japan, and colleagues created a magnetic alloy that under certain conditions lacks magnetism. In ordinary magnets, both individual electron spins and the motion of electrons in their atomic orbitals generate magnetic fields. Combined, these fields produce the materials total magnetic field. In some rare-earth elements, though, the two contributions are nearly identical. With that in mind, Adachis group created an alloy from aluminum and samarium, a rare-earth element having opposite spin and orbital moments that vary with temperature. They found that at temperatures just above and below 70 degrees Kelvin, they could readily magnetize the SmAl2 alloy using an external magnetic field. But at precisely 70 degrees Kelvin, the spin and orbital moments in the material cancelled each other out. The alloy wont find uses on refrigerators or as compass needles, but the scientists suggest it may have applications in spintronicsa new class of electronic devices that harness electron spins instead of charge

Scientists Grow Heart Cells from Embryonic Stem Cells

U.S. researchers at the Technion-Israel Institute of Technology announced that they have successfully turned embryonic stem cell cells into the heart cells. Their results appear in the August issue of the Journal of Clinical Investigation. The scientists started with a line of embryonic stem cells and first grew a mass of undifferentiated cells. They then moved the cells into a suspension containing growth factors designed to encourage differentiated growth. While dividing, the stem cells consolidated into so-called embryoid bodies, or microscopic clumps of cells. The researchers noticed that approximately 10 percent of these bodies contained cells that were spontaneously contractinga signature of cells called cardiomyocytes that develop into heart tissue in an embryo.

To test whether what they had created were in fact cardiomyocytes, the researchers ran a variety of tests. They analyzed the electrical and chemical activities of the cells, examined their structure with an electron microscope, investigated their responses to hormones such as adrenaline, and probed the genes and proteins within the cells. Comparing the results to known cardiomyocytes suggested that they had successfully cultured the cells.