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Background This study aimed to explore the experiences and needs of (ex-)welfare benefit recipients from a large urban municipality in the Netherlands regarding their welfare-to-work services and their case workers. Methods Quantitative data from a client satisfaction survey that was filled out by 213 people (response rate 11%) who received welfare-to-work services was combined with results from four group interviews with a total of 15 people receiving welfare-to-work services. Verbatim transcripts from the interviews were analysed using inductive thematic analysis. Results The survey results showed that most clients were reasonably satisfied with the welfare-to-work services they received. Four main themes emerged from the interviews: (1) experiences and needs related to the interactions between case workers and benefit recipients; (2) the need for tailored services; (3) the complicating role of the system the case workers operate within; and (4) the existence of differences between case workers regarding how strict they followed the rules and to what extent they connected with their clients on a personal level. Conclusions Our findings show that clients were reasonably satisfied with the welfare-to-work services provided by their municipality but that there is still room for improvement. Case workers should have good social skills to build a trusting relationship with the client, welfare-to-work services should be tailored to the individual, and clear concise information should be given to welfare benefit recipients, especially with regard to what benefit recipients can expect of the municipality and the case workers, given their dual role in supporting (re-)integration to work and monitoring benefit eligibility.

The developments on the North Sea offer opportunities to strengthen the economy of the Province of South Holland and to improve the spatial quality of the environment. With this research, the Province of South Holland gains better insight into the developments on and surrounding the North Sea that can influence and shape the provincial ambitions. Based on expected trends and developments on and surrounding the North Sea and related stakeholders’ visions, ambitions and opportunities, we develop four scenarios for the future of the Province of South Holland, building on the North Sea scenarios developed by PBL (2018, 2019). For each of these scenarios, we provide insight into the expected economic and spatial impacts as well as an overview of the social challenges, the possible policy instruments and the related roles & responsibilities that these scenarios entail. These scenarios form the basis for the definition of no-regret policy recommendations regarding developments and opportunities related to activities on sea, on the coast and in the port. With this we put topics on the agenda for the development of a coherent (future) economic and spatial-environmental policy for the Province of South Holland., De ontwikkelingen op de Noordzee bieden kansen om de economie in de Provincie Zuid-Holland te versterken en de ruimtelijke omgevingskwaliteit te verbeteren. Met dit onderzoek krijgt de Provincie Zuid-Holland een beter inzicht in de ontwikkelingen op en rond de Noordzee die de provinciale ambities kunnen beïnvloeden en vormen. Op basis van verwachte trends en ontwikkelingen op en rond de Noordzee en gerelateerde visies, ambities en kansen van stakeholders ontwikkelen we, uitgaande van de Noordzeescenario’s ontwikkeld door PBL (2018, 2019), vier scenario’s voor de toekomst voor de Provincie Zuid-Holland. Voor ieder van deze scenario’s geven wij inzicht in de verwachte economische en ruimtelijke impacts evenals een overzicht van de maatschappelijke opgaven, de mogelijke beleidsinstrumenten en de gerelateerde rollen & verantwoordelijkheden die deze scenario’s met zich meebrengen. Deze scenario’s vormen de basis voor de definitie van no-regret beleidsaanbevelingen rond ontwikkelingen en kansen gerelateerd aan activiteiten op zee, aan de kust en in de haven. Hiermee agenderen wij onderwerpen voor het ontwikkelen van een samenhangend (toekomstig) economische en ruimtelijke omgevingsbeleid van de Provincie Zuid-Holland.

RIVM rapport:In 2009 heeft VWS, via het Centrum voor Infectieziektebestrijding (CIb) van het RIVM een subsidie beschikbaar gesteld, voor de periode 2009-2011, om te investeren in initiatieven op het gebied van voorlichting over seksuele gezondheid onder allochtonen. De projectsubsidie is uitgezet via GGD'en waarbij de financiële middelen gelijkmatig zijn verdeeld over de acht bestaande soa/Sense-regio's. Om inzicht te verkrijgen in de effectiviteit van de wijze waarop de projectsubsidie is ingericht en werd uitgevoerd heeft ResCon in opdracht van het CIb een procesevaluatie uitgevoerd. Voor het onderzoek zijn semigestructureerde interviews gehouden met het RIVM-CIb, enkele betrokken landelijke instellingen, alle acht subsidiecoördinatoren en vier lokale GGD-coördinatoren, en in elke soa/Sense-regio één lokale organisatie waarmee is samengewerkt. De manier van subsidieverstrekking heeft in potentie tot effectieve projecten geleid, waarmee een relatief grote groep allochtonen is bereikt. De insteek waarbij GGD'en samenwerking moesten zoeken met lokale organisaties lijkt vruchtbaar te zijn geweest voor het bereiken van de doelgroep en voor het vergroten van de kennis over de doelgroep bij de GGD'en. Uit het onderzoek blijkt bovendien dat er in alle soa/Sense-regio's een basis is gelegd voor de toekomstige aanpak van de seksuele gezondheid van allochtonen. Bepaalde projecten vinden doorgang na het beëindigen van de projectsubsidie, zij het in sterk afgeslankte vorm, binnen Sense hulpverlening aan jongeren. GGD-medewerkers zijn zich bewuster geworden van de problematiek die speelt bij de doelgroep(en) en er zijn contacten met lokale organisaties gerealiseerd. Wel is vervolgfinanciering nodig om de blijvende problematiek op het gebied van seksuele gezondheid bij allochtonen aan te pakken. Meer voorbereidingstijd voor aanvang van de subsidie had ervoor kunnen zorgen dat GGD'en beter onderbouwde aanvragen hadden kunnen indienen en dat het RIVM-CIb zijn coördinerende rol beter had kunnen, In 2009 the Ministry of Public Health (VWS) provided a subsidy for the period of two and a half years in order to improve sexual health among ethnic minorities in the Netherlands. The subsidy was coordinated by the Centre for Infectious Disease Control (CIb) and distributed equally among eight existing regions providing sexcounseling and STI-clinics. In these regions the Public Health Services (PHSs) were responsible for the projects. The RIVM-CIb has requested ResCon to conduct a process evaluation in order to assess the effectiveness of the establishment and implementation of the subsidy. For this study semi-structured interviews were carried out with the coordinator from RIVM-CIb, stakeholders from national health-related institutions, all eight subsidy coordinators and four regional PHD coordinators, and in each region one local organisation. The study shows that the subsidy has resulted in potentially effective projects reaching a relatively large group of ethnic minorities. The approach, in which PHSs were obliged to cooperate with local organisations, seemed to be a productive way of reaching the target group and increasing the knowledge of the target group within the PHSs. Moreover, the knowledge of local organisations contributed to a better adjustment of projects to the needs of ethnic minority groups. In all regions a basis has formed for future projects on sexual health directed at ethnic minorities as illustrated by several youth projects that continued even when the subsidy ended. Also, contacts with local organizations have been realized in these regions. Depending on the nature of the projects and the financial means projects are often continued at the end of the subsidy period. More time to prepare for the start of the subsidy period would have enabled the PHS's to submit higher quality proposal and RIVM-CIb to fulfil a stronger coordinating role. Additionally, more support from non-governmental institutions could have enhanced benefits of the proje

In 2009 heeft VWS, via het Centrum voor Infectieziektebestrijding (CIb) van het RIVM een subsidie beschikbaar gesteld, voor de periode 2009-2011, om te investeren in initiatieven op het gebied van voorlichting over seksuele gezondheid onder allochtonen. De projectsubsidie is uitgezet via GGD'en waarbij de financiële middelen gelijkmatig zijn verdeeld over de acht bestaande soa/Sense-regio's. Om inzicht te verkrijgen in de effectiviteit van de wijze waarop de projectsubsidie is ingericht en werd uitgevoerd heeft ResCon in opdracht van het CIb een procesevaluatie uitgevoerd. Voor het onderzoek zijn semigestructureerde interviews gehouden met het RIVM-CIb, enkele betrokken landelijke instellingen, alle acht subsidiecoördinatoren en vier lokale GGD-coördinatoren, en in elke soa/Sense-regio één lokale organisatie waarmee is samengewerkt. De manier van subsidieverstrekking heeft in potentie tot effectieve projecten geleid, waarmee een relatief grote groep allochtonen is bereikt. De insteek waarbij GGD'en samenwerking moesten zoeken met lokale organisaties lijkt vruchtbaar te zijn geweest voor het bereiken van de doelgroep en voor het vergroten van de kennis over de doelgroep bij de GGD'en. Uit het onderzoek blijkt bovendien dat er in alle soa/Sense-regio's een basis is gelegd voor de toekomstige aanpak van de seksuele gezondheid van allochtonen. Bepaalde projecten vinden doorgang na het beëindigen van de projectsubsidie, zij het in sterk afgeslankte vorm, binnen Sense hulpverlening aan jongeren. GGD-medewerkers zijn zich bewuster geworden van de problematiek die speelt bij de doelgroep(en) en er zijn contacten met lokale organisaties gerealiseerd. Wel is vervolgfinanciering nodig om de blijvende problematiek op het gebied van seksuele gezondheid bij allochtonen aan te pakken. Meer voorbereidingstijd voor aanvang van de subsidie had ervoor kunnen zorgen dat GGD'en beter onderbouwde aanvragen hadden kunnen indienen en dat het RIVM-CIb zijn coördinerende rol beter had kunnen, In 2009 the Ministry of Public Health (VWS) provided a subsidy for the period of two and a half years in order to improve sexual health among ethnic minorities in the Netherlands. The subsidy was coordinated by the Centre for Infectious Disease Control (CIb) and distributed equally among eight existing regions providing sexcounseling and STI-clinics. In these regions the Public Health Services (PHSs) were responsible for the projects. The RIVM-CIb has requested ResCon to conduct a process evaluation in order to assess the effectiveness of the establishment and implementation of the subsidy. For this study semi-structured interviews were carried out with the coordinator from RIVM-CIb, stakeholders from national health-related institutions, all eight subsidy coordinators and four regional PHD coordinators, and in each region one local organisation. The study shows that the subsidy has resulted in potentially effective projects reaching a relatively large group of ethnic minorities. The approach, in which PHSs were obliged to cooperate with local organisations, seemed to be a productive way of reaching the target group and increasing the knowledge of the target group within the PHSs. Moreover, the knowledge of local organisations contributed to a better adjustment of projects to the needs of ethnic minority groups. In all regions a basis has formed for future projects on sexual health directed at ethnic minorities as illustrated by several youth projects that continued even when the subsidy ended. Also, contacts with local organizations have been realized in these regions. Depending on the nature of the projects and the financial means projects are often continued at the end of the subsidy period. More time to prepare for the start of the subsidy period would have enabled the PHS's to submit higher quality proposal and RIVM-CIb to fulfil a stronger coordinating role. Additionally, more support from non-governmental institutions could have enhanced benefits of the proje

RIVM rapport:In 2009 heeft VWS, via het Centrum voor Infectieziektebestrijding (CIb) van het RIVM een subsidie beschikbaar gesteld, voor de periode 2009-2011, om te investeren in initiatieven op het gebied van voorlichting over seksuele gezondheid onder allochtonen. De projectsubsidie is uitgezet via GGD'en waarbij de financiële middelen gelijkmatig zijn verdeeld over de acht bestaande soa/Sense-regio's. Om inzicht te verkrijgen in de effectiviteit van de wijze waarop de projectsubsidie is ingericht en werd uitgevoerd heeft ResCon in opdracht van het CIb een procesevaluatie uitgevoerd. Voor het onderzoek zijn semigestructureerde interviews gehouden met het RIVM-CIb, enkele betrokken landelijke instellingen, alle acht subsidiecoördinatoren en vier lokale GGD-coördinatoren, en in elke soa/Sense-regio één lokale organisatie waarmee is samengewerkt. De manier van subsidieverstrekking heeft in potentie tot effectieve projecten geleid, waarmee een relatief grote groep allochtonen is bereikt. De insteek waarbij GGD'en samenwerking moesten zoeken met lokale organisaties lijkt vruchtbaar te zijn geweest voor het bereiken van de doelgroep en voor het vergroten van de kennis over de doelgroep bij de GGD'en. Uit het onderzoek blijkt bovendien dat er in alle soa/Sense-regio's een basis is gelegd voor de toekomstige aanpak van de seksuele gezondheid van allochtonen. Bepaalde projecten vinden doorgang na het beëindigen van de projectsubsidie, zij het in sterk afgeslankte vorm, binnen Sense hulpverlening aan jongeren. GGD-medewerkers zijn zich bewuster geworden van de problematiek die speelt bij de doelgroep(en) en er zijn contacten met lokale organisaties gerealiseerd. Wel is vervolgfinanciering nodig om de blijvende problematiek op het gebied van seksuele gezondheid bij allochtonen aan te pakken. Meer voorbereidingstijd voor aanvang van de subsidie had ervoor kunnen zorgen dat GGD'en beter onderbouwde aanvragen hadden kunnen indienen en dat het RIVM-CIb zijn coördinerende rol beter had kunnen, In 2009 the Ministry of Public Health (VWS) provided a subsidy for the period of two and a half years in order to improve sexual health among ethnic minorities in the Netherlands. The subsidy was coordinated by the Centre for Infectious Disease Control (CIb) and distributed equally among eight existing regions providing sexcounseling and STI-clinics. In these regions the Public Health Services (PHSs) were responsible for the projects. The RIVM-CIb has requested ResCon to conduct a process evaluation in order to assess the effectiveness of the establishment and implementation of the subsidy. For this study semi-structured interviews were carried out with the coordinator from RIVM-CIb, stakeholders from national health-related institutions, all eight subsidy coordinators and four regional PHD coordinators, and in each region one local organisation. The study shows that the subsidy has resulted in potentially effective projects reaching a relatively large group of ethnic minorities. The approach, in which PHSs were obliged to cooperate with local organisations, seemed to be a productive way of reaching the target group and increasing the knowledge of the target group within the PHSs. Moreover, the knowledge of local organisations contributed to a better adjustment of projects to the needs of ethnic minority groups. In all regions a basis has formed for future projects on sexual health directed at ethnic minorities as illustrated by several youth projects that continued even when the subsidy ended. Also, contacts with local organizations have been realized in these regions. Depending on the nature of the projects and the financial means projects are often continued at the end of the subsidy period. More time to prepare for the start of the subsidy period would have enabled the PHS's to submit higher quality proposal and RIVM-CIb to fulfil a stronger coordinating role. Additionally, more support from non-governmental institutions could have enhanced benefits of the proje

RIVM rapport:In 2009 heeft VWS, via het Centrum voor Infectieziektebestrijding (CIb) van het RIVM een subsidie beschikbaar gesteld, voor de periode 2009-2011, om te investeren in initiatieven op het gebied van voorlichting over seksuele gezondheid onder allochtonen. De projectsubsidie is uitgezet via GGD'en waarbij de financiële middelen gelijkmatig zijn verdeeld over de acht bestaande soa/Sense-regio's. Om inzicht te verkrijgen in de effectiviteit van de wijze waarop de projectsubsidie is ingericht en werd uitgevoerd heeft ResCon in opdracht van het CIb een procesevaluatie uitgevoerd. Voor het onderzoek zijn semigestructureerde interviews gehouden met het RIVM-CIb, enkele betrokken landelijke instellingen, alle acht subsidiecoördinatoren en vier lokale GGD-coördinatoren, en in elke soa/Sense-regio één lokale organisatie waarmee is samengewerkt. De manier van subsidieverstrekking heeft in potentie tot effectieve projecten geleid, waarmee een relatief grote groep allochtonen is bereikt. De insteek waarbij GGD'en samenwerking moesten zoeken met lokale organisaties lijkt vruchtbaar te zijn geweest voor het bereiken van de doelgroep en voor het vergroten van de kennis over de doelgroep bij de GGD'en. Uit het onderzoek blijkt bovendien dat er in alle soa/Sense-regio's een basis is gelegd voor de toekomstige aanpak van de seksuele gezondheid van allochtonen. Bepaalde projecten vinden doorgang na het beëindigen van de projectsubsidie, zij het in sterk afgeslankte vorm, binnen Sense hulpverlening aan jongeren. GGD-medewerkers zijn zich bewuster geworden van de problematiek die speelt bij de doelgroep(en) en er zijn contacten met lokale organisaties gerealiseerd. Wel is vervolgfinanciering nodig om de blijvende problematiek op het gebied van seksuele gezondheid bij allochtonen aan te pakken. Meer voorbereidingstijd voor aanvang van de subsidie had ervoor kunnen zorgen dat GGD'en beter onderbouwde aanvragen hadden kunnen indienen en dat het RIVM-CIb zijn coördinerende rol beter had kunnen, In 2009 the Ministry of Public Health (VWS) provided a subsidy for the period of two and a half years in order to improve sexual health among ethnic minorities in the Netherlands. The subsidy was coordinated by the Centre for Infectious Disease Control (CIb) and distributed equally among eight existing regions providing sexcounseling and STI-clinics. In these regions the Public Health Services (PHSs) were responsible for the projects. The RIVM-CIb has requested ResCon to conduct a process evaluation in order to assess the effectiveness of the establishment and implementation of the subsidy. For this study semi-structured interviews were carried out with the coordinator from RIVM-CIb, stakeholders from national health-related institutions, all eight subsidy coordinators and four regional PHD coordinators, and in each region one local organisation. The study shows that the subsidy has resulted in potentially effective projects reaching a relatively large group of ethnic minorities. The approach, in which PHSs were obliged to cooperate with local organisations, seemed to be a productive way of reaching the target group and increasing the knowledge of the target group within the PHSs. Moreover, the knowledge of local organisations contributed to a better adjustment of projects to the needs of ethnic minority groups. In all regions a basis has formed for future projects on sexual health directed at ethnic minorities as illustrated by several youth projects that continued even when the subsidy ended. Also, contacts with local organizations have been realized in these regions. Depending on the nature of the projects and the financial means projects are often continued at the end of the subsidy period. More time to prepare for the start of the subsidy period would have enabled the PHS's to submit higher quality proposal and RIVM-CIb to fulfil a stronger coordinating role. Additionally, more support from non-governmental institutions could have enhanced benefits of the proje

We have studied the magnetic configuration in ultrathin antiferromagnetic Mn films grown around monoatomic steps on an Fe( 001) surface by spin-polarized scanning tunnelling microscopy/spectroscopy and ab initio-parameterized self-consistent real-space tight-binding calculations in which the spin quantization axis is independent for each site, thus allowing noncollinear magnetism. Mn grown on Fe( 001) presents a layered antiferromagnetic structure. In the regions where the Mn films overgrows Fe steps the magnetization of the surface layer is reversed across the steps. Around these defects a frustration of the antiferromagnetic order occurs. Due to the weakened magnetic coupling at the central Mn layers, the amount of frustration is smaller than in Cr, and the width of the wall induced by the step does not change with the thickness, at least for coverages up to seven monolayers.

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Contains fulltext : 33007.pdf (publisher's version ) (Open Access)

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RU,, 28 april 2005, Promotores : van Kempen, H., Nolte, R.J.M. Co-promotores : Elemans, J.A.A.W., Hendriks, P., Contains fulltext : 26913_softinsor.pdf (publisher's version ) (Open Access), While knowledge creation lies at the heart of scientific research, the role of knowledge typically remains implicit in studies of the practices and the management of that research. This paper examines which critical success factors (CSF's) define successful research. Based on Nonaka's knowledge spiral, it examines how processes of knowledge creation contribute to the existence or absence of success as indicated by these CSF's. It presents the outcomes of an in-depth exploration of the workings of the knowledge spiral in a university research institute. The research shows the outstanding but undervalued importance of socialization processes, whereas the most widely recognized tokens of success in academic research, given its focus on output, lie in externalization. It also shows that, while research success is typically defined at the interplay of the individual, group and institutional level, in the case organization none of the four knowledge creation processes (socialization, externalization, combination and internalization) appears to run smoothly at the institutional level

Item does not contain fulltext

Item does not contain fulltext

Contains fulltext : 33156.pdf (publisher's version ) (Closed access)

Contains fulltext : 33007.pdf (publisher's version ) (Open Access)

Item does not contain fulltext

RU,, 28 april 2005, Promotores : van Kempen, H., Nolte, R.J.M. Co-promotores : Elemans, J.A.A.W., Hendriks, P., Contains fulltext : 26913_softinsor.pdf (publisher's version ) (Open Access), While knowledge creation lies at the heart of scientific research, the role of knowledge typically remains implicit in studies of the practices and the management of that research. This paper examines which critical success factors (CSF's) define successful research. Based on Nonaka's knowledge spiral, it examines how processes of knowledge creation contribute to the existence or absence of success as indicated by these CSF's. It presents the outcomes of an in-depth exploration of the workings of the knowledge spiral in a university research institute. The research shows the outstanding but undervalued importance of socialization processes, whereas the most widely recognized tokens of success in academic research, given its focus on output, lie in externalization. It also shows that, while research success is typically defined at the interplay of the individual, group and institutional level, in the case organization none of the four knowledge creation processes (socialization, externalization, combination and internalization) appears to run smoothly at the institutional level

Item does not contain fulltext

Contains fulltext : 33156.pdf (publisher's version ) (Closed access)

Contains fulltext : 33007.pdf (publisher's version ) (Open Access)

Item does not contain fulltext

RU,, 28 april 2005, Promotores : van Kempen, H., Nolte, R.J.M. Co-promotores : Elemans, J.A.A.W., Hendriks, P., Contains fulltext : 26913_softinsor.pdf (publisher's version ) (Open Access), While knowledge creation lies at the heart of scientific research, the role of knowledge typically remains implicit in studies of the practices and the management of that research. This paper examines which critical success factors (CSF's) define successful research. Based on Nonaka's knowledge spiral, it examines how processes of knowledge creation contribute to the existence or absence of success as indicated by these CSF's. It presents the outcomes of an in-depth exploration of the workings of the knowledge spiral in a university research institute. The research shows the outstanding but undervalued importance of socialization processes, whereas the most widely recognized tokens of success in academic research, given its focus on output, lie in externalization. It also shows that, while research success is typically defined at the interplay of the individual, group and institutional level, in the case organization none of the four knowledge creation processes (socialization, externalization, combination and internalization) appears to run smoothly at the institutional level

Contains fulltext : 58913.pdf (preprint version ) (Open Access), Results of an experimental study of palladium nanojunctions in a hydrogen environment are presented. Two new hydrogen-related atomic configurations are found, which have conductances of similar to0.5 and similar to1 quantum unit (2e(2)/h). Phonon spectrum measurements demonstrate that these configurations are situated between electrodes containing dissolved hydrogen. The crucial differences compared to the previously studied Pt-H-2 junctions and the possible microscopic realizations of the new configurations in palladium-hydrogen atomic-sized contacts are discussed.

Contains fulltext : 57910.pdf (publisher's version ) (Open Access), We deposit a laser-collimated chromium beam onto a substrate through a quasiperiodic laser standing-wave (SW) tuned above the atomic resonance at the Cr-52 transition S-7(3)-->P-7(4)o at 425.55 nm. This SW is created by interference of five laser beams crossing in one point at mutual angles of 72degrees. The resulting chromium pattern on the substrate surface mimics the geometry of the SW and it is thus itself quasiperiodic. On a surface area of 0.2x0.2 mm(2) the spatial Fourier spectrum of the measured patterns is decagonal. Besides being of fundamental interest, this quasiperiodic nanofabrication via atom optics can find its applications in photonics.

Contains fulltext : 58476.pdf (publisher's version ) (Open Access), We used the mechanically controllable break junction technique to discriminate between the electric field and temperature effects in the process of surface modification. The electric field strength at the surface of electrodes was accurately determined using the field emission resonance spectra and was gradually raised to the point where surface modification starts. We found that only a limited number of metals with large values of the work function, greater than or similar to4.5-5 eV, and evaporation fields, less than or similar to1.5-2 V/Angstrom, can be modified in this way. Adsorption of He on the surface drastically increases the local work function of material and enables the field induced nanostructuring of the electrode surface practically for all metals. (C) 2004 American Institute of Physics.

Contains fulltext : 57909.pdf (preprint version ) (Open Access), The conductance of breaking metallic nanojunctions shows plateaus alternated with sudden jumps, corresponding to the stretching of stable atomic configurations and atomic rearrangements. We investigate the structure of the conductance plateaus both by measuring the voltage dependence of the plateaus' slope on individual junctions and by a detailed statistical analysis on a large amount of contacts. Though the atomic discreteness of the junction plays a fundamental role in the evolution of the conductance, we find that the fine structure of the conductance plateaus is determined by quantum interference phenomenon to a great extent.

Contains fulltext : 58913.pdf (preprint version ) (Open Access), Results of an experimental study of palladium nanojunctions in a hydrogen environment are presented. Two new hydrogen-related atomic configurations are found, which have conductances of similar to0.5 and similar to1 quantum unit (2e(2)/h). Phonon spectrum measurements demonstrate that these configurations are situated between electrodes containing dissolved hydrogen. The crucial differences compared to the previously studied Pt-H-2 junctions and the possible microscopic realizations of the new configurations in palladium-hydrogen atomic-sized contacts are discussed.

Contains fulltext : 57910.pdf (publisher's version ) (Open Access), We deposit a laser-collimated chromium beam onto a substrate through a quasiperiodic laser standing-wave (SW) tuned above the atomic resonance at the Cr-52 transition S-7(3)-->P-7(4)o at 425.55 nm. This SW is created by interference of five laser beams crossing in one point at mutual angles of 72degrees. The resulting chromium pattern on the substrate surface mimics the geometry of the SW and it is thus itself quasiperiodic. On a surface area of 0.2x0.2 mm(2) the spatial Fourier spectrum of the measured patterns is decagonal. Besides being of fundamental interest, this quasiperiodic nanofabrication via atom optics can find its applications in photonics.

Contains fulltext : 58476.pdf (publisher's version ) (Open Access), We used the mechanically controllable break junction technique to discriminate between the electric field and temperature effects in the process of surface modification. The electric field strength at the surface of electrodes was accurately determined using the field emission resonance spectra and was gradually raised to the point where surface modification starts. We found that only a limited number of metals with large values of the work function, greater than or similar to4.5-5 eV, and evaporation fields, less than or similar to1.5-2 V/Angstrom, can be modified in this way. Adsorption of He on the surface drastically increases the local work function of material and enables the field induced nanostructuring of the electrode surface practically for all metals. (C) 2004 American Institute of Physics.

Contains fulltext : 57909.pdf (preprint version ) (Open Access), The conductance of breaking metallic nanojunctions shows plateaus alternated with sudden jumps, corresponding to the stretching of stable atomic configurations and atomic rearrangements. We investigate the structure of the conductance plateaus both by measuring the voltage dependence of the plateaus' slope on individual junctions and by a detailed statistical analysis on a large amount of contacts. Though the atomic discreteness of the junction plays a fundamental role in the evolution of the conductance, we find that the fine structure of the conductance plateaus is determined by quantum interference phenomenon to a great extent.

Contains fulltext : 57909.pdf (preprint version ) (Open Access), The conductance of breaking metallic nanojunctions shows plateaus alternated with sudden jumps, corresponding to the stretching of stable atomic configurations and atomic rearrangements. We investigate the structure of the conductance plateaus both by measuring the voltage dependence of the plateaus' slope on individual junctions and by a detailed statistical analysis on a large amount of contacts. Though the atomic discreteness of the junction plays a fundamental role in the evolution of the conductance, we find that the fine structure of the conductance plateaus is determined by quantum interference phenomenon to a great extent.

Contains fulltext : 58476.pdf (publisher's version ) (Open Access), We used the mechanically controllable break junction technique to discriminate between the electric field and temperature effects in the process of surface modification. The electric field strength at the surface of electrodes was accurately determined using the field emission resonance spectra and was gradually raised to the point where surface modification starts. We found that only a limited number of metals with large values of the work function, greater than or similar to4.5-5 eV, and evaporation fields, less than or similar to1.5-2 V/Angstrom, can be modified in this way. Adsorption of He on the surface drastically increases the local work function of material and enables the field induced nanostructuring of the electrode surface practically for all metals. (C) 2004 American Institute of Physics.

Contains fulltext : 58913.pdf (preprint version ) (Open Access), Results of an experimental study of palladium nanojunctions in a hydrogen environment are presented. Two new hydrogen-related atomic configurations are found, which have conductances of similar to0.5 and similar to1 quantum unit (2e(2)/h). Phonon spectrum measurements demonstrate that these configurations are situated between electrodes containing dissolved hydrogen. The crucial differences compared to the previously studied Pt-H-2 junctions and the possible microscopic realizations of the new configurations in palladium-hydrogen atomic-sized contacts are discussed.

Contains fulltext : 57910.pdf (publisher's version ) (Open Access), We deposit a laser-collimated chromium beam onto a substrate through a quasiperiodic laser standing-wave (SW) tuned above the atomic resonance at the Cr-52 transition S-7(3)-->P-7(4)o at 425.55 nm. This SW is created by interference of five laser beams crossing in one point at mutual angles of 72degrees. The resulting chromium pattern on the substrate surface mimics the geometry of the SW and it is thus itself quasiperiodic. On a surface area of 0.2x0.2 mm(2) the spatial Fourier spectrum of the measured patterns is decagonal. Besides being of fundamental interest, this quasiperiodic nanofabrication via atom optics can find its applications in photonics.

Contains fulltext : 92610.pdf (publisher's version ) (Closed access)

Contains fulltext : 92610.pdf (publisher's version ) (Closed access)

We have performed optical spectroscopy measurements on a STM-tip-induced quantum dot in a GaAs layer. The dominant confinement in the (hole) quantum dot is found to be in the direction parallel to the tip axis. Electron confinement is achieved by a sub-surface AlGaAs barrier. Current-dependent measurements indicate that many-body interactions can cause spectral blueshifts up to 75 meV for a tunneling current of 10 nA. Consequently, a full treatment of the many-body problem is required for an accurate description of this type of system.

We demonstrate a spectroscopic technique which is based on ballistic injection of minority carriers from the lip of a scanning-tunneling microscope into a semiconductor heterostructure. Ey analyzing the resulting electroluminescence spectrum as a function of tip-sample bias, both the injection barrier height and the carrier scattering rate, in the semiconductor can be determined. This technique is complementary to ballistic electron emission spectroscopy since minority instead of majority carriers are injected, which give the opportunity to study the carrier trajectory after injection.

We present a novel spectroscopic technique that is based on the ballistic injection of minority carriers from the tip of a scanning-tunneling microscope into a semiconductor heterostructure. By analyzing the resulting electro-luminescence spectrum as a function of tip-sample bias, both the injection barrier height and the carrier relaxation rate Gamma(s) after injection can be determined. At 4.2 K we found Gamma(s) = 5 x 10(13) s(-1) and at 77 K we found Gamma(s) = 8 x 10(13) s(-1). From current-dependent measurements we find that, at room temperature, a large fraction of the carriers is trapped prior to radiative recombination. At high currents or low temperatures the traps become saturated. We tentatively identify the Be acceptors in the structure as trapping centers.

We have designed and built a low-temperature (1.3-4.2 K) scanning-tunneling microscope which is capable of collecting light that is generated in the tunneling region. Light collection is done by means of two fibers whose cleaved front is in close proximity (approximate to1 mm) to the tunneling region. The whole system can be operated in high magnetic fields (11 T) without loss of optical signal strength. As a demonstration, we measured the electroluminescence spectra of an InGaAs quantum well at various temperatures. At 4.2 K, we found an electron-to-photon conversion factor that is three orders of magnitude higher than at room temperature. (C) 2001 American Institute of Physics.

We present a novel spectroscopic technique which is based on the ballistic injection of minority carriers from the tip of an STM into a semiconductor heterostructure. By analyzing the resulting electro-luminescence spectrum as a function of tip-sample bias, both the injection barrier height and the carrier relaxation rate Gamma (s) after injection can be determined. From current dependent measurements we find that carrier trapping by impurities causes a significant non-radiative recombination channel at room temperature.

We have performed optical spectroscopy measurements on an STM-tip-induced quantum dot. The dominant confinement in the (hole) quantum dot is in the direction parallel to the tip axis. Electron confinement is achieved by a sub-surface AlGaAs barrier. Current dependent measurements indicate that many-body interactions can cause spectral blue-shifts up to 75 meV.

Spectrally resolved scanning tunneling microscope-induced luminescence has been obtained under ambient conditions, i.e., at room temperature, in air, by passivating the sample surface with sulfur. This passivation turned out to be essential to suppress the local anodic oxidation induced by the tunneling current. From the dependence of the luminescence signal on tunneling current and voltage, we find that the passivation solution and post-passivation annealing temperature strongly modify the surface density of states (SDOS). More specifically, we found evidence that, after annealing at 400 degrees C, no SDOS is left above the bottom of the conduction band. For annealing at 200 degrees C, the SDOS is found to be extended up to 1.0 +/- 0.2 eV above the bottom of the conduction band. In all cases, the passivated (001) surface appears to be completely pinned. (C) 1999 American Institute of Physics. [S0003-6951(99)01949-X].