Self-assembly of compositionally modulated Ga1−xMnxAs multilayers during molecular beam epitaxy

Abstract

GaMnAs structures were grown on GaAs(100) substrates by molecular beam epitaxy employing different growth parameters. We studied manganese incorporation employing secondary ion mass spectrometry (SIMS). At a growth temperature of 300 °C, we observed a self-assembled modulation of the manganese concentration. SIMS depth profiles were analyzed employing a depth resolution function taking into account sputtering-induced broadening of the original distribution and segregation. We found a Mn segregation length along the growth direction of ∼4 nm. The presence of GaMnAs multilayers was corroborated by high-resolution x-ray diffraction. Spinodal decomposition is a possible mechanism for the spontaneous formation of the multilayer structure.

Self-assembly of correlated (Ti, V)O2 superlattices with tunable lamella periods by kinetically enhanced spinodal decomposition

“…Unlike nucleation and growth, spinodal decomposition is a unique thermodynamic, diffusion-controlled phenomenon that leads to spontaneous formation of multiple phases from a uniform mixture, and the process occurs due to longrange spatial and periodic compositional modulations on the nanometer scale. This unique feature of spinodal decomposition has been exploited to obtain highly periodic nanostructures, e.g., self-assembled two-dimensional superlattices in III-V semiconductors [12][13][14] , metal alloys 15,16 , and transition metal oxides [17][18][19] systems.…”

Дельта-легирование соединениями марганца гетероструктур на основе GaAs

“…Для того чтобы преодолеть эффект " пока-чивания", наблюдаемый в высококачественных монокри-сталлических образцах [13], вместо обычного одиноч-ного сканирования была выбрана проекция величины соотношения ω/2θ как функция от угла ω. Модели-рование и подгонка кривых качания были выполнены с помощью программы X'pert Epitaxy and Smoothfit. Полученные значения толщин квантовой ямы InGaAs и барьерных слоев GaAs контролировались с помощью изображений поперечного сечения гетероструктуры, по-лученных методом просвечивающей электронной микро-скопии (ПЭМ).…”

Spinodal decomposition introduces strain-enhanced thermochromism in polycrystalline V1−xTixO2 thin films

“…3 The most prominent feature of SD is its capacity to assemble anisotropic condensed matter into ordered multilayers or even superlattices (SLs) without layer-by-layer epitaxy. [4][5][6] A notable example of SD ordering is provided by the strongly anisotropic VO 2 -TiO 2 system. 7 The compositional wave in V 1−x Ti x O 2 propagates along the c-axis of the rutile structure (c R ), producing a layered nanocomposite with alternating V-and Ti-rich phases.…”

“…3 The most prominent feature of SD is its capacity to assemble anisotropic condensed matter into ordered multilayers or even superlattices (SLs) without layer-by-layer epitaxy. 4–6…”