Neither 2D nor 3D. The new technology could be in between


APE Beamline (ph. Massimo Belluz)

An international team composed by researchers from Italian CNR, Princeton University and University of Hiroshima discovered that TMDs (Transition Metal Dichalcogenides) behave neither as strictly two-dimensional materials (like for instance graphene) nor as common three-dimensional materials (like the “old” silicon).

These materials attract significant attention due to their extraordinary properties, in particular ‘titanic’ magnetoresistance, almost one million times larger than the ‘giant’ one, whose discovery brought the Nobel prize to the scientists Grünberg and Fert.

The researcher was conducted at Elettra Sincrotrone Trieste, in AREA Science Park, and published in Nature Communications.



Neither 2D nor 3D, the future technological materials would be halfway in between the bidimensional materials (such as graphene) and the three-dimensional ones (the well known and exploited silicon). This is the conclusion of the research that was recently performed by a team composed by researchers from Italy (Iom and Spin Institutes of the Italian National Research Council),United States (Princeton University) and Japan (University of Hiroshima). The team was engaged in the investigation of the electronic properties of Transition Metal Dichalcogenides (TMDs), a category of materials that has recently attracted a significant attention of the scientific community due to their extraordinary properties. The study that took place at Elettra Sincrotrone Trieste has recently been published in Nature Communications.

“The TMDs are versatile materials that can be exfoliated, just like graphene, and their thickness can be reduced to a few millionth parts of millimeter. One of them, the subject of the present research, possesses an extraordinary magnetoresistance, the property of the materials to vary (significantly) their electrical resistance as a function of applied magnetic field, already widely exploited in the new generation of electronic devices.” , explains the CNR-IOM researcher Ivana Vobornik. “The common belief is that the properties of TMDs are basically driven by their two-dimensionality. Our work is the first to prove that it is not completely true”.

The research team utilized the synchrotron light from the Elettra storage ring to investigate Tungsten Ditelluride, a TMD with ‘titanic’ magnetoresistance, almost one million times larger than the ‘giant’ one nowadays exploited in the newest generation hard disk drives (for the discovery of giant magnetoresistance P. Grünberg and A. Fert won the Nobel prize in 2007). The analysis of the experimental data demonstrates that the electronic properties of tungsten ditelluride are not perfectly bidimensional.

“The layers of this material are not independent, but do interact among themselves to drive its peculiar properties. The ‘titanic’ magnetoresistance can be explained if at least three layers are taken into account”, concludes Vobornik. “The next step will be to verify whether this 2D-3D ambiguity represents a general property of TMDs and other materials on which the current scientific research is investing”. 

Nature Communications 7, Article number:10847 doi:10.1038/ncomms10847

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Last Updated on Thursday, 24 March 2016 16:37