Direct imaging of long-range ferromagnetic and antiferromagnetic order in a dipolar metamaterial

Magnetic metamaterials such as artificial spin ice offer a route to tailor magnetic properties. Such materials can be fabricated by lithographically defining arrays of nanoscale magnetic islands. The magnetostatic interactions between the elements are influenced by their shape and geometric arrangement and can lead to long-range ordering. We demonstrate how the magnetic order in a two-dimensional periodic array of circular disks is controlled by the lattice symmetry. Antiferromagnetic and ferromagnetic order extending through the entire array is observed for the square and hexagonal lattice, respectively. Furthermore, we show that a minute deviation from perfect circularity of the elements along a preferred direction results in room-temperature blocking and favors collinear spin textures

Micromagnetic modelling and magnetic force microscopy of supermagnetism in patterned nanomagnetic arrays

Advanced magnetic materials have played an important role in, and continue to pave the way for, innovative technological advancements. Modern day computers, sensors, and biomedicine would not be possible without the use of such materials. Assemblies of magnetic metamaterials, comprised of a complex microscopic structure, presents a new and promising opportunity to specifically tailor nearly all magnetic properties of a material. This thesis presents an in-depth, multipronged attempt at understanding and creating specific instances of such magnetic materials with emergent ensemble properties. Micromagnetic modeling of stable (and ground) states of such structures have been carried out. The simulation results are used to predict and verify the observation of physical instances of corresponding structures. Emergent superferromagnetic and super- antiferromagnetic behavior was found for structures of different lattice geometries, in two-dimensional, patterned permalloy thin film. Of note is the long-range order of the superferromagnetic states and the indication that certain structures can be coerced into both superferromagnetic and superantiferromagnetic metastable states. Physical structures of ordered nanomagnets were designed and later fabricated at NTNU NanoLab s cleanroom facilities. The samples were inspected through the use of magnetic force microscopy at cryogenic temperatures and subjected to varying applied magnetic fields in order to classify the structures behavior. A stable, physical, super- ferromagnetic state was clearly observed and classified for triangular lattice geometries. Similar states were found for square lattice geometries, in addition to indication of the presence of a switchable superantiferromagnetic state. Additionally, several auxiliary results were obtained and auspicious suggestions for further work is provided

Tilrettelegging for egenvurdering av digital kompetanse

Digital kompetanse har fått oppmerksomhet både nasjonalt og internasjonalt, og er utpekt som en av nøkkelkompetansene for livslang læring. Digital kompetanse er essensiell for deltakelse i det stadig voksende digitale samfunn, og må revideres i takt med teknologiutviklingen. I denne sammenhengen er det nødvendig å kunne administrere kompetanseutvikling på egenhånd. Denne undersøkelsen er en del av et større utviklingsarbeid som jobber ut fra problemstillingen: ”Hvordan tilrettelegge for egenvurdering av digital kompetanse?”. Litteraturen viser til et behov for en klart formulert standard som legger til rette for egenvurdering av digital kompetanse. Undersøkelsen utvikler, på bakgrunn av dette behovet, et egenvurderingssystem forankret i litteraturen omkring digital kompetanse og egenvurdering. Formålet med denne undersøkelsen er å belyse forskningsspørsmålet: Kan man, ved å knytte klare spørsmål og kriterier opp mot prestasjoner i en oppgaveløsning, tilrettelegge for en mer presis egenvurdering, enn gjennom klare kriterier og spørsmål alene? Undersøkelsen forsøker å belyse forskningsspørsmålet gjennom en analyse av skriftlige dokumenter, samlet inn gjennom kvasieksperimentelt design. I kvasieksperimentet vurderer hver informant sin egen digitale kompetanse før og etter en intervensjon. Intervensjonen i kvasieksperimentet er oppgaver som informantene løser. I egenvurderingen etter intervensjonen vurderer informantene egne prestasjoner opp mot deres oppgaveløsning. Egenvurderingen til informantene før og etter intervensjonen, i tillegg til oppgavebesvarelser, ble samlet inn og videre kategorisert og gradert gjennom en kvalitativ dokumentanalyse. Funn fra undersøkelsen viser til avvik og likheter mellom informantenes egenvurdering før og etter intervensjonen, i tillegg til å vise flest avvik mellom vurderingen av informantenes digitale kompetanse og deres egenvurdering. Mulige årsaksforklaringer på disse funnene kobles opp mot oppgavenes oppfattede vanskelighetsgrad, uklare spørsmål og kriterier, konteksten oppgavene gir informantene og utvalgets kvaliteter.Master i IKT-støttet lærin

Tilrettelegging for egenvurdering av digital kompetanse

Digital kompetanse har fått oppmerksomhet både nasjonalt og internasjonalt, og er utpekt som en av nøkkelkompetansene for livslang læring. Digital kompetanse er essensiell for deltakelse i det stadig voksende digitale samfunn, og må revideres i takt med teknologiutviklingen. I denne sammenhengen er det nødvendig å kunne administrere kompetanseutvikling på egenhånd. Denne undersøkelsen er en del av et større utviklingsarbeid som jobber ut fra problemstillingen: ”Hvordan tilrettelegge for egenvurdering av digital kompetanse?”. Litteraturen viser til et behov for en klart formulert standard som legger til rette for egenvurdering av digital kompetanse. Undersøkelsen utvikler, på bakgrunn av dette behovet, et egenvurderingssystem forankret i litteraturen omkring digital kompetanse og egenvurdering. Formålet med denne undersøkelsen er å belyse forskningsspørsmålet: Kan man, ved å knytte klare spørsmål og kriterier opp mot prestasjoner i en oppgaveløsning, tilrettelegge for en mer presis egenvurdering, enn gjennom klare kriterier og spørsmål alene? Undersøkelsen forsøker å belyse forskningsspørsmålet gjennom en analyse av skriftlige dokumenter, samlet inn gjennom kvasieksperimentelt design. I kvasieksperimentet vurderer hver informant sin egen digitale kompetanse før og etter en intervensjon. Intervensjonen i kvasieksperimentet er oppgaver som informantene løser. I egenvurderingen etter intervensjonen vurderer informantene egne prestasjoner opp mot deres oppgaveløsning. Egenvurderingen til informantene før og etter intervensjonen, i tillegg til oppgavebesvarelser, ble samlet inn og videre kategorisert og gradert gjennom en kvalitativ dokumentanalyse. Funn fra undersøkelsen viser til avvik og likheter mellom informantenes egenvurdering før og etter intervensjonen, i tillegg til å vise flest avvik mellom vurderingen av informantenes digitale kompetanse og deres egenvurdering. Mulige årsaksforklaringer på disse funnene kobles opp mot oppgavenes oppfattede vanskelighetsgrad, uklare spørsmål og kriterier, konteksten oppgavene gir informantene og utvalgets kvaliteter

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

Flatspin: a large-scale artificial spin ice simulator

We present flatspin, a novel simulator for systems of interacting mesoscopic spins on a lattice, also known as artificial spin ice (ASI). A generalization of the Stoner-Wohlfarth model is introduced, and combined with a well-defined switching protocol to capture realistic ASI dynamics using a point-dipole approximation. Temperature is modelled as an effective thermal field, based on the Arrhenius-Neel equation. Through GPU acceleration, flatspin can simulate the dynamics of millions of magnets within practical time frames, enabling exploration of large-scale emergent phenomena at unprecedented speeds. We demonstrate flatspin's versatility through the reproduction of a diverse set of established experimental results from literature. In particular, the field-driven magnetization reversal of "pinwheel" ASI is reproduced, for the first time, in a dipole model. Finally, we use flatspin to explore aspects of "square" ASI by introducing dilution defects and measuring the effect on the vertex population

Clocked dynamics in artificial spin ice

Artificial spin ice (ASI) are nanomagnetic metamaterials with a wide range of emergent properties. ASI systems have recently shown promise as substrates for novel computing devices. A precondition for computation is the ability to control how the artificial spins change their state over time. Detailed control of the state evolution in ASI systems has proven difficult. Here, we introduce astroid clocking, a global field protocol that carefully exploits the intrinsic switching astroids of the nanomagnets to selectively address spins within the ASI. The resulting clocked dynamics is characterized by discrete, gradual evolution of spin states. We demonstrate, both experimentally and in simulations, how astroid clocking of pinwheel ASI allows ferromagnetic domains to be gradually grown or reversed at will. More complex dynamics arise when the clock protocol allows both growth and reversal to occur within the same clock cycle. Astroid clocking offers unprecedented control of ASI dynamics in both time and space, and enables new directions in ASI research and beyond