MOSCOW, September 24. /TASS/. An international group of researchers, which included physicists from Immanuel Kant Baltic Federal University, conducted an experiment confirming the effectiveness of the method of contactless temperature measurement of materials which are promising for use in medicine and other fields, the press service of the university told TASS on Thursday.
Compounds with a magnetocaloric effect are "smart" materials, the properties of which in the future will make it possible to create on their basis such inventions as new generation implants with controlled release of drugs or eco-friendly CFC-free refrigerators. In order to do so, scientists need to study the quality of the material in detail, however, the temperature of such compounds is traditionally measured by direct contact of the compounds with an external magnetic field, which is a limitation for conducting research under certain conditions. The authors of the study were able to improve the temperature measurement process by testing a recently proposed contactless method.
"Contactless methods of studying the magnetocaloric effect are necessary in cases where it is technically impossible to use standard contact temperature meters - a thermometer or a thermocouple. This is especially important for studying the magnetocaloric effect in micro- and nanoscale objects. <...> A team of researchers from Immanuel Kant Baltic Federal University, together with their colleagues from the University of Parma (Italy) and the Dresden Laboratory of High Magnetic Fields at the Helmholtz Research Center (Germany), conducted a joint study on one of the promising magnetocaloric alloys using a new contactless method proposed earlier by Italian colleagues," the statement reads.
The conceot of the new method is the use of a thermo-optical effect, known as the "mirage effect", in which deviations of the laser beam passing through a surface close to the object are observed, caused by changes in the temperature of the studied sample. The authors of the study compared the technique with two other methods of measuring temperature — using a thermocouple and through measuring the heat capacity using well-known thermodynamic relations. An alloy of iron and rhodium was chosen as an experimental sample.
"It is important that the proposed method can be successfully implemented to study the smart composite materials and alloys we obtain — from massive samples to tapes and films. The results obtained using the contactless method do not contradict the results <...> of using classical methods. Thus, we have demonstrated that an alternative contactless method of temperature measurement can be successfully applied to conduct our tasks," the press service of the university quotes Karim Amirov, a senior researcher at the laboratory of new magnetic materials at Immanuel Kant Baltic Federal University.
The results of the study, supported by a grant from the Russian Science Foundation, are published in the Journal of Applied Physics.