Reentrant Behavior of the Density vs. Temperature of Indium Islands on GaAs(111)A

• Main Authors: Artur Tuktamyshev, Alexey Fedorov, Sergio Bietti, Shiro Tsukamoto, Roberto Bergamaschini, Francesco Montalenti, Stefano Sanguinetti
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Nanomaterials
• Subjects: droplet epitaxy; GaAs(111)A; indium islands; RHEED; liquid-solid transition
• Online Access: https://www.mdpi.com/2079-4991/10/8/1512

We show that the density of indium islands on GaAs(111)A substrates have a non-monotonic, reentrant behavior as a function of the indium deposition temperature. The expected increase in the density with decreasing temperature, indeed, is observed only down to 160 <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula>C, where the indium islands undertake the expected liquid-to-solid phase transition. Further decreasing the temperature causes a sizable reduction of the island density. An additional reentrant increasing behavior is observed below 80 <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula>C. We attribute the above complex behavior to the liquid–solid phase transition and to the complex island–island interaction which takes place between crystalline islands in the presence of strain. Indium solid islands grown at temperatures below 160 <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula>C have a face-centered cubic crystal structure.