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Crystal film growth: nanosheets extend epitaxial growth applications

Date:
December 19, 2013
Source:
International Center for Materials Nanoarchitectonics (MANA)
Summary:
Molecularly thin two-dimensional crystals can alleviate the lattice matching restrictions of epitaxial crystalline thin film growth, new research shows.
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Schematic illustration of nanosheet structures for Ca2Nb3O10-, Ti0.87O20.52-, and MoO2δ− nanosheets and corresponding crystal planes of SrTiO3.
Credit: Image courtesy of International Center for Materials Nanoarchitectonics (MANA)

Molecularly thin two-dimensional crystals can alleviate the lattice matching restrictions of epitaxial crystalline thin film growth, new research shows.

Epitaxial growth has become increasingly important for growing crystalline thin films with tailored electronic, optical and magnetic properties for technological applications. However the approach is limited by the high structural similarities required between an underlying substrate and a growing crystal layer on top of it.

Takayoshi Sasaki and colleagues at the International Center for Materials Nanoarchitectonics (MANA) and the University of Tokyo in Japan demonstrate how using two-dimensional materials they can extend the versatility of epitaxial growth techniques.

In 1984 Komo proposed that certain layered materials such as mica or graphite can be easily cleaved to produce surfaces with no dangling bonds that would alleviate the lattice matching requirements for epitaxial growth.

Interactions between adatoms on these cleaved materials would be more prominent compared with growth on single crystalline substrates since the interlayer van der Waals interactions are weak. However the variety of suitable cleaved surfaces is limited and handling them can be difficult.

With the increasing attention on two-dimensional materials over recent years Takayoshi Sasaki and colleagues decided to look into molecularly thin two-dimensional crystals as possible seed layers to alleviate lattice matching requirements in a manner similar to Komo's van der Waals epitaxy.

They deposited nanosheets of either Ca2Nb3O10-, Ti0.87O20.52-, or MoO2δ- as highly organised layers onto amorphous glass. On these different surfaces they grew different orientations of SrTiO3, an important perovskite for various technological applications. The approach demonstrated the ability to grow different orientations of SrTiO3 with a high level of precision.

The researchers suggest that in the future, it would be of great interest to achieve more sophisticated control of growth geometry using nanosheets with a complex structure. They add, "Such advanced design, hardly realized with present technology, will pave a new way for further development of crystal engineering."


Story Source:

The above post is reprinted from materials provided by International Center for Materials Nanoarchitectonics (MANA). Note: Materials may be edited for content and length.


Journal Reference:

  1. Tatsuo Shibata, Hikaru Takano, Yasuo Ebina, Dae Sung Kim, Tadashi C. Ozawa, Kosho Akatsuka, Tsuyoshi Ohnishi, Kazunori Takada, Toshihiro Kogure, Takayoshi Sasaki. Versatile van der Waals epitaxy-like growth of crystal films using two-dimensional nanosheets as a seed layer: orientation tuning of SrTiO3 films along three important axes on glass substrates. Journal of Materials Chemistry C, 2014; 2 (3): 441 DOI: 10.1039/C3TC31787K

Cite This Page:

International Center for Materials Nanoarchitectonics (MANA). "Crystal film growth: nanosheets extend epitaxial growth applications." ScienceDaily. ScienceDaily, 19 December 2013. <www.sciencedaily.com/releases/2013/12/131219154413.htm>.
International Center for Materials Nanoarchitectonics (MANA). (2013, December 19). Crystal film growth: nanosheets extend epitaxial growth applications. ScienceDaily. Retrieved September 5, 2015 from www.sciencedaily.com/releases/2013/12/131219154413.htm
International Center for Materials Nanoarchitectonics (MANA). "Crystal film growth: nanosheets extend epitaxial growth applications." ScienceDaily. www.sciencedaily.com/releases/2013/12/131219154413.htm (accessed September 5, 2015).

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