Integrating sustainability in an electronic engineering program: insights and experiences on academic staff involvement

There is a growing urgency to incorporate sustainability in all facets of society to stay within the planetary boundaries. Higher education has a significant role by educating their students - our future work forces – with the knowledge and competences that are crucial for working with sustainability challenges. The development of sustainable technology thereby takes a significant place, pointing out the role of engineering education. This article presents the journey of integrating sustainability in the M.Sc programme Electronic System Design and Innovation at the Norwegian University of Science and Technology. We focus on three aspects of this journey. First, we present the approach used and the process stages for the integration of sustainability, which is a renewed version of a toolbox for integrating ecodesign in engineering studies. Secondly, we present how academic staff is involved throughout the integration process. To be able to succeed with incorporating sustainability into a study programme, it is important to engage and empower academic staff, since they have a central position through their responsibility for a study’s central building blocks - the different courses. Lastly, we outline insights and experiences from the perspective of academic staff and the project team involved in the integration process. We conclude with how the approach used and the lessons learned can provide useful strategic and practical insights for other engineering programmes in their process of integrating sustainability and plans for future activities

Synthesis and characterization of (111)- oriented perovskite oxide heterostrctures

The limits of silicon in semiconductor devices are fast approaching, with feature sizes reaching the realm where quantum effects start to dominate. A promising approach is to include materials with new functionality such as ferromagnetism and ferroelectricity, creating more energy efficient and tailored electronic devices. Perovskite oxides are interesting for this purpose due to their wide range of available functional properties and strong coupling between structure and functionality, opening for property control through depositing these materials as thin films on suitably chosen substrates. Although a significant amount of research has been devoted to exploring this class of materials, the effect of growing on different substrate crystal orientations is not well understood. In this study we focus on films and substrates cut along the pseudocubic (111)-facet. While the more commonly used (001)-orientation has a square symmetry, the (111)-orientation has a hexagonal symmetry. Additionally, employing the (111)-orientation results in altered oxygen octahedra connectivity across interfaces and different geometrical boundary conditions compared to the (001)-orientation. These properties of the (111)-orientation can induce interesting topological properties, novel phases such as polar metals, and enhanced interfacial exchange coupling. In this work, we study how the symmetry, strain, and interface morphology of the pseudocubic (111)-orientation affects the properties of ferromagnetic and ferroelectric perovskite oxides. Ferromagnetic La0.7Sr0.3MnO3 and ferroelectric BaTiO3 is chosen as model materials. Thin films are deposited on a variety of single crystal substrates using pulsed laser deposition. Both La0.7Sr0.3MnO3 and BaTiO3 are grown on SrTiO3, while La0.7Sr0.3MnO3 is additionally deposited on DyScO3 and NdGaO3 in order to study the effects of (111)-oriented strain on the magnetic properties. To achieve high quality thin film synthesis, control over the substrate surfaces is important. Treatments of SrTiO3, DyScO3, GdScO3, and NdGaO3 substrates are developed and optimized, resulting in atomically flat step-and-terrace surfaces, providing for layer-by-layer growth of perovskite thin films. While the step heights of the SrTiO3 surface correspond to one (111) interplanar distance due its cubic symmetry, the step heights of the orthorhombic substrates, DyScO3, GdScO3, and NdGaO3, can be tailored to be either one or two (111) interplanar distances depending on the specific (111)-orientation used. Analysis of the film growth indicates that the surfaces are reconstructed due to the polar stacking along the [111]-orientation, which can result in an intermixed layer at the substrate and thin film interface. The application of strain provides an avenue towards control of both structural and functional properties. A range of strain values are applied by employing DyScO3, SrTiO3, and NdGaO3 as substrates for deposition of epitaxial La0.7Sr0.3MnO3, enabling investigation into (111)-orientated strain. Moreover, the effects of different (111)-oriented in-plane symmetries are studied by exploiting the fact that SrTiO3 possesses a different crystal structure than DyScO3 and NdGaO3. We use various experimental techniques to probe the magnetic properties of the La0.7Sr0.3MnO3 films and find the respective easy and hard axes through the shape of the hysteresis curves. It is found through reciprocal space maps that La0.7Sr0.3MnO3 can assume rhombohedral, monoclinic, or triclinic unit cells depending on the applied strain and substrate symmetry. We link the observed anisotropy and structure through theoretical models of magnetic anisotropy. The step and terrace structure is shown to be important for the magnetic anisotropy of La0.7Sr0.3MnO3 on SrTiO3, where a uniaxial anisotropy is found at remanence. Through measuring the magnetic properties of La0.7Sr0.3MnO3, we find the direction of the anisotropy is dependent on the film thickness. The easy axis is aligned perpendicular to the step edges below a critical thickness while in thicker films the easy axis lies parallel to the step edges. The magnetic anisotropy is additionally sensitive to the structural phase transition of the SrTiO3 substrate at 105 K, and a sharp increase of the anisotropy constant in the tetragonal phase is observed. For both the strain and step and terrace induced anisotropies we hypothesize that octahedral rotations along with the crystal structure are necessary to explain the results. By creating theoretical phase diagrams of the magnetic anisotropy as a function of octahedral tilt, it is shown that induced octahedral rotations can explain the observed results, indicating that the octahedral response to (111)-orientated strain and morphology is different from films in the (001)-orientation. The growth of (111)-oriented BaTiO3 is found to be dominated by defect formation. Films of 10 nm and thicker are completely relaxed in-plane, with indications of higher defect density with increasing film thickness. Signs of ferroelectricity are observed in films of thickness down to 5 nm. As in La0.7Sr0.3MnO3, the properties of BaTiO3 is found to be sensitive to the structural phase transition of the SrTiO3 substrate, with an marked change in the measured pyroelectric current at 105 K. Through material synthesis, experimental characterization, and theoretical models, we have gained further insight into (111)-orientated perovskite material systems. We are successful in preparing high quality (111)-oriented substrates facilitating the deposition of thin films. The crystal structure and magnetic anisotropy of the films are found to be highly susceptible to (111)- oriented strain, substrate symmetry, and interface morphology. Lastly, we explore the growth and properties of (111)-oriented BaTiO3. The presented results demonstrate that utilization of the (111)-orientation is an interesting avenue in the development of functional material systems for use in future electronic devices

Fabrication of a Silicon Photonic Crystal Biosensor

The research performed in the scope of the master project and described in this thesis is devoted to the study of a two dimensional photonic crystal biosensor in silicon. The band gap of hexagonal photonic crystal slab structures is simulated using MIT Photonic-Bands (MPB) and the dependence of slab thickness, substrate and hole depth is found. The effect of relevant fabrication errors are investigated with COMSOL Multiphysics. It is found that even small fabrication errors leads to a resonance peak split.The photonic crystal is fabricated using a focused ion beam (FIB) system. The effect of ion beam energy, current and dwell time on the fabricated holes are studied on uncovered silicon samples and silicon samples covered with 40nm titanium dioxide and 100nm silicon dioxide thin films. The best result was achieved for a titanium dioxide covered sample milled with 30kV ions at a current of 9pA, a dwell time of 1ms, and a dose of 666.65 pC per square micro meter yielding a sidewall angle of 3.2 degrees. Cross section of the milled holes reveas that the FIB produced very smooth hole sidewalls. Patterning of a silicon oxide hard mask with FIB for inductively coupled plasma reactive ion etching (ICP-RIE) is investigated. It is found that the used etch chemistry (SF6/CHF3) gives very poor selectivity and is unsuitable for this purpose.Input and output waveguides along with a plateau to support the photonic crystal is constructed using an electron beam lithography (EBL) and ICP-RIE process adapted from previous work at NTNU. Reproducing the results are proved difficult, finally achieving a sidewall roughness of approximately 10nm.The full structure of waveguides and photonic crystal sensor is fabricated using a combination of EBL and FIB milling. The results are the best achieved at NTNU for use in photonic crystals with regards to hole shape and sidewall smoothness

Do Students Reflect on Sustainability? Student Development of Competencies for Sustainability in Project-Based Learning

Higher education plays a crucial role in supporting a society based on sustainable development through the facilitation of students’ acquisition of competencies for sustainable development. A suitable arena in which to integrate these competencies can be courses built on project-based learning, though knowing how to support the students’ learning can be difficult and a continued challenge. In this work, we study first and second year bachelor level PBL courses and examine the effect of choosing a project theme related to sustainability. Specifically, we look at the students’ own assessment of integration of sustainability aspects in their projects, and their development of the normative competency, critical thinking competency, and self-awareness competency fromUNESCO’s key competencies for sustainability, as a function of project theme. Through a survey, where students were asked to assess themselves and their own projects on a seven-point Likert scale, we found that while having sustainability-related project themes does have some effect, the effect is limited compared to the development of other competencies in the course. Along with how the project theme affects the development of the investigated competencies, the need for targeted support in order to facilitate the students’ development of sustainability related competencies is discussed

Sustainability in project-based learning: Project themes and self- perceived competencies

Project-based learning can be a suitable arena in which to integrate sustainability. In this work, we study what effect choosing a project theme related to sustainability has on the students’ own assessment of integration of sustainability aspects in their projects, and their development of the normative, critical thinking, and self-awareness competencies from UNESCO’s key competencies for sustainability. It is found that while having sustainability-related project themes does have some effect, the effect is limited compared to the development of other competencies in the course

Thickness dependent uniaxial magnetic anisotropy due to step-edges in (1 1 1)-oriented La0.7Sr0.3MnO3 thin films

The magnetic anisotropy of films of La0.7Sr0.3MnO3 grown on vicinal (1 1 1)-oriented SrTiO3 substrates are investigated. For temperatures above the tetragonal – cubic structural phase transition temperature of the substrate, a step edge induced uniaxial magnetic anisotropy is found at remanence, with a thickness-driven change in easy axis direction, from perpendicular to the step edges to parallel to the step edges with increasing thickness. The anisotropy constant for the investigated (1 1 1)-oriented samples is of the same magnitude as for previously reported (0 0 1)-oriented samples. The data is discussed in the framework of in-plane rotations of the oxygen octahedra resulting in a uniaxial anisotropy. Furthermore, the magnetic anisotropy is sensitive to the structural phase transition at 105 K of the substrate, and the anisotropy constant increases drastically as the temperature is lowered below 105 K

Magneto-dynamic properties of complex oxide—La0.7Sr0.3MnO3/SrTiO3— heterostructure interface

We have studied the interface magnetodynamic properties of La0.7Sr0.3MnO3/SrTiO3 (111) heterostructures by Ferromagnetic resonance spectroscopy (FMR). In addition to the bulk FMR mode, the measurements indicate a mode originating from an independently excited ferromagnetic layer at the interface. The peak-to-peak intensity of the interface mode suggests a layer thickness on the order of few unit cells. Angle resolved FMR measurements reveal a hexagonal symmetry of the magnetocrystalline anisotropy of the mode with the easy axis along the in-plane crystallographic directions matching with the (111) surface orientation of the substrate, in contrast to bulk mode symmetry which is always found to have uniaxial symmetry caused by magnetostriction. The temperature dependence of the anisotropy and a large temperature variation in the intensity ratio of interface and bulk mode indicate a coupling of the interface to the bulk mode

Emergent premises in student experiences of a first-year electrical engineering course

This study explores how project-based learning in combination with other pedagogical scaffolding approaches influences students’ experiences during their transition into the university. Based on the thematic analysis of interviews with students at the end of the first semester, we show how a project-based course in electronics can create opportunities within three themes: student socialisation, curriculum integration, and peer-learning. In the light of these findings, we discuss how students build relationships with other students, as well as with faculty members and practicing engineers, and how these relationships influence their start at the university. On a more general level, this case study exemplifies how an existing electrical engineering programme can be changed by targeted interventions without the need for programme wide adjustments

Aktivitetsbasert emneorganisering

I artikkelen deler vi våre første erfaringer med aktivitetsbasert emne­organi­sering som ble prøvd ut på et stort innføringsemne for sivilingeniørstudenter ved NTNU. Den grunnleggende ideen er at for å fremme studentaktiv læring, må både undervisere og studenter endre sine tanker og forventninger om hvordan et emne er organisert, både innen hver enkelt læringsøkt og over tid