Crystal phase engineering: the “art” of creating materials with tailor made properties by playing with their crystal structure
Nowadays materials science faces an even more ambitious task: creating materials by design, that is engineering materials with tailor made properties, typically because they can be useful for some specific applications. A way to achieve this goal is creating superlattices, periodic structures made of an ordered sequence of building blocks of different materials, whose properties that can be tuned by controlling the stacking of the building blocks. In the framework of a collaborative research project led by Ilaria Zardo, from the University of Basel (Switzerland), counting with the collaboration of the Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) (Spain), the Universitat Autònoma de Barcelona (UAB) (Spain) and the Technical University of Eindhoven (The Netherlands), the tuning of the vibrational properties of a crystal phase superlattice has been demonstrated for the first time. This superlattice is different from the conventional ones, since its basic LEGO® bricks used as building blocks, rather than made of different materials, are made of different crystal phases of the same material. This finding has been published in the journal Nano Letters and highlighted by the editor in the journal cover .
This discovery paves the way to exciting future developments, because the interfaces between different materials are often rough and defected, while those between different crystal structures of the same material are remarkably sharp and clean, a crucial feature for many applications. Until today, however, it was under debate if these novel systems could behave as conventional superlattices.