Тип публикации: статья из журнала
Год издания: 2019
Идентификатор DOI: 10.1021/acs.cgd.9b00609
Аннотация: The GdFe3(BO3)(4) crystal has attracted great interest as a magnetic-field-induced multiferroic. In this paper, we show that the multiferroic properties in this crystal can be induced by high pressure. At high pressures up to 50 GPa, created in diamond anvil cells, the structural and vibrational (phonon) properties of the GdFe3(BO3Показать полностью)(4) crystal were studied. The structural phase transition was detected at about 23-25 GPa by Raman and synchrotron Mossbauer (NFS) spectroscopy. First-principle calculations of the crystal lattice dynamics at pressures below and above the structural transition were carried out. It was established that at pressures above the structural transition, the space group R32 of GdFe3(BO3)(4) is changed to the polar space group R3, and the crystal becomes a ferroelectric. At the R32 -> R3 transition, the displacement of the boron ion B(2) and oxygen O results in the formation of boron-oxygen B(2)O-4 tetrahedrons instead of the plane BO3 triangles. Meanwhile, the triangle oxygen environment of boron in the site B(1) remains unchanged. The nearest environment of the gadolinium ion also changes significantly. Instead of six oxygen ions in the R32 phase, the nearest surroundings of Gd in the R3 phase consist of nine oxygen ions forming a complex polyhedron. A large hysteresis of the transition indicates that this crystal remains a ferroelectric with a decrease in pressure to about ambient pressure.
Журнал: CRYSTAL GROWTH & DESIGN
Выпуск журнала: Vol. 19, Is. 12
Номера страниц: 6935-6944
ISSN журнала: 15287483
Место издания: WASHINGTON
Издатель: AMER CHEMICAL SOC