researchers from the department of materials science and engineering at texas a&m university (college station) have discovered a special class of two-dimensional materials that feature two ferroic characteristics simultaneously and could be used to continue the miniaturization and high-performance of electronic devices.
dr. xiaofeng qian, an assistant professor, and hua wang, a graduate student in the department, were featured in a recent issue of 2d materials for their work in 2d multiferroic materials. (texas a&m university)
according to a report on the school’s website, the 2-d semiconductors demonstrated both ferroelasticity (large spontaneous lattice strain) and ferroelectricity (a giant switchable electric polarization) at the same time. the properties appeared simultaneously in monolayer group iv monochalcogenides led to 2-d “ferroelastic-ferroelectric multiferroicity.”
the article explained, “this unique class of 2d multiferroic materials could be useful for 2d ferroelectric memory and ferroelastic memory that are as thin as one nanometer. in pocket-sized devices, this new material could help make the device smaller by decreasing the size of the sensors and materials inside the device. they can also be useful for exploring ferroelectric excitonic photovoltaics that take advantage of both large ferroelectricity and extraordinary excitonic optical absorption.”
the researchers also believe that these materials can lead to a platform for 2-d nonvolatile, photonic memory with low power consumption at a faster speed. they will be working on tuning the ferroic properties to meet real-world applications.
the work was published in 2d materials. the abstract stated:
“low-dimensional multiferroics with strongly coupled ferroic orders are highly valuable for miniaturized transducers, actuators, sensors, photovoltaics, and nonvolatile memories. however, they are very scarce owing to the stringent symmetry and chemistry requirements for practical applications at room temperature.
“using first-principles theory, we predict that two-dimensional monolayer group iv monochalcogenides including ges, gese, sns, and snse are a class of 2d semiconducting multiferroics with giant strongly coupled in-plane spontaneous ferroelectric polarization and spontaneous ferroelastic lattice strain.
“in addition, they are thermodynamically stable at room temperature, and possess strong anisotropic and excitonic in-plane photoabsorption with visible-spectrum excitonic gaps and large exciton binding energies.
“the interplay of low domain wall energy, small migration barrier, coupled ferroelastic-ferroelectric order, and anisotropic electronic structures suggest their great potential for tunable multiferroic functional devices by manipulating external electrical, mechanical, and optical field to control the internal responses.”
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