| Autor: |
Barreto RR; Physics Department, Federal University of Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil. rogerio.paniago0@gmail.com., Ribeiro TC; Physics Department, Federal University of Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil. rogerio.paniago0@gmail.com., Soares GHR; Physics Department, Federal University of Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil. rogerio.paniago0@gmail.com., Pereira E; Physics Department, Federal University of Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil. rogerio.paniago0@gmail.com., Miquita DR; Microscopic Center, Federal University of Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil., Safar GAM; Physics Department, Federal University of Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil. rogerio.paniago0@gmail.com., Mazzoni MSC; Physics Department, Federal University of Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil. rogerio.paniago0@gmail.com., Malachias A; Physics Department, Federal University of Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil. rogerio.paniago0@gmail.com., Magalhaes-Paniago R; Physics Department, Federal University of Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil. rogerio.paniago0@gmail.com. |
| Abstrakt: |
The discovery of ferroelectricity in two-dimensional van der Waals materials has sparked enormous interest from the scientific community, due to its possible applications in next-generation nanoelectronic devices, such as random-access memory devices, digital signal processors, and solar cells, among others. In the present study, we used vapor phase deposition to synthesize ultrathin germanium sulfide nano-flakes on a highly oriented pyrolytic graphite substrate. Nanostructures of variable thicknesses were characterized using scanning tunneling microscopy and spectroscopy. Tunneling currents under forward and backward biases were measured as a function of nano-flake thickness. Remarkably, we clearly observed a hysteresis pattern, which we attributed to surface ferroelectric behavior, consistent with the screening conditions of polarization charges. The effect increases as the number of layers is reduced. This experimental result may be directly applicable to miniaturized memory devices, given the two-dimensional nature of this effect. |
