Malindretos, Jörg

[["dc.bibliographiccitation.firstpage","95"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","physica status solidi (RRL) - Rapid Research Letters"],["dc.bibliographiccitation.lastpage","97"],["dc.bibliographiccitation.volume","5"],["dc.contributor.author","Segura-Ruiz, J."],["dc.contributor.author","Martinez-Criado, G."],["dc.contributor.author","Sans, J. A."],["dc.contributor.author","Tucoulou, R."],["dc.contributor.author","Cloetens, P."],["dc.contributor.author","Snigireva, I."],["dc.contributor.author","Denker, C."],["dc.contributor.author","Malindretos, Joerg"],["dc.contributor.author","Rizzi, Angela"],["dc.contributor.author","Gomez-Gomez, M. I."],["dc.contributor.author","Garro, N."],["dc.contributor.author","Cantarero, A."],["dc.date.accessioned","2018-11-07T08:58:39Z"],["dc.date.available","2018-11-07T08:58:39Z"],["dc.date.issued","2011"],["dc.description.abstract","Using synchrotron radiation nanoprobe, this work reports on the elemental distribution in single In(x)Ga(1-x)N nanowires (NWs) grown by molecular beam epitaxy directly on Si(111) substrates. Single NWs dispersed on Al covered sapphire were characterized by nano-X-ray fluorescence, Raman scattering and photoluminescence spectroscopy. Both Ga and In maps reveal an inhomogeneous axial distribution inside single NWs. The analysis of NWs from the same sample but with different dimensions suggests a decrease of In segregation with the reduction of NW diameter, while Ga distribution seems to remain unaltered. Photoluminescence and Raman scattering measurements carried out on ensembles of NWs exhibit relevant signatures of the compositional disorder. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim"],["dc.description.sponsorship","NANOWIRING [265073]"],["dc.identifier.doi","10.1002/pssr.201004527"],["dc.identifier.isi","000288178800003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23695"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1862-6254"],["dc.title","Direct observation of elemental segregation in InGaN nanowires by X-ray nanoprobe"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1706"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","physica status solidi (c)"],["dc.bibliographiccitation.lastpage","1708"],["dc.bibliographiccitation.volume","5"],["dc.contributor.author","Denker, Christian"],["dc.contributor.author","Malindretos, Joerg"],["dc.contributor.author","Werner, Florian"],["dc.contributor.author","Limbach, Friederich"],["dc.contributor.author","Schuhmann, Henning"],["dc.contributor.author","Niermann, Tore"],["dc.contributor.author","Seibt, Michael"],["dc.contributor.author","Rizzi, Angela"],["dc.date.accessioned","2021-12-08T12:30:42Z"],["dc.date.available","2021-12-08T12:30:42Z"],["dc.date.issued","2008"],["dc.identifier.doi","10.1002/pssc.200778596"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/96525"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-476"],["dc.relation.eissn","1610-1642"],["dc.relation.issn","1610-1634"],["dc.rights.uri","http://doi.wiley.com/10.1002/tdm_license_1.1"],["dc.title","Self-organized growth of InN-nanocolumns on p-Si(111) by MBE"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","012108"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","AIP Advances"],["dc.bibliographiccitation.volume","2"],["dc.contributor.author","Broxtermann, Daniel"],["dc.contributor.author","Sivis, Murat"],["dc.contributor.author","Malindretos, Jörg"],["dc.contributor.author","Rizzi, Angela"],["dc.date.accessioned","2018-11-07T09:12:36Z"],["dc.date.available","2018-11-07T09:12:36Z"],["dc.date.issued","2012"],["dc.description.abstract","We have grown 2DEG AlGaN/GaN heterostructures by molecular beam epitaxy (MBE) with electron mobilities up to 21500 cm(2)V(-1)s(-1) at 2 K. In-situ RHEED was applied to optimize different aspects of Ga-rich growth. This paper gives a compact overview of the experimental key aspects that significantly affect the low temperature electron mobility in AlGaN/GaN heterostructures. Growth at the transition towards Ga droplet formation produced the best results. A quantitative analysis of the magnetoresistance confirmes scattering at dislocations as the dominant scattering process at low temperature. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [doi: 10.1063/1.3679149]"],["dc.description.sponsorship","DFG [SFB 602]"],["dc.identifier.doi","10.1063/1.3679149"],["dc.identifier.fs","590413"],["dc.identifier.isi","000302225400026"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9558"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26975"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","2158-3226"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","MBE growth of high electron mobility 2DEGs in AlGaN/GaN heterostructures controlled by RHEED"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1348"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Semiconductor Science and Technology"],["dc.bibliographiccitation.lastpage","1353"],["dc.bibliographiccitation.volume","21"],["dc.contributor.author","Kocan, M."],["dc.contributor.author","Malindretos, Joerg"],["dc.contributor.author","Roever, Martin"],["dc.contributor.author","Zenneck, J."],["dc.contributor.author","Niermann, T."],["dc.contributor.author","Mai, D. D."],["dc.contributor.author","Bertelli, M."],["dc.contributor.author","Seibt, M."],["dc.contributor.author","Rizzi, Angela"],["dc.date.accessioned","2018-11-07T09:24:01Z"],["dc.date.available","2018-11-07T09:24:01Z"],["dc.date.issued","2006"],["dc.description.abstract","GaMnN layers have been grown by MBE on Si(111) in a wide range of growth conditions. For different substrate temperatures the structural and composition dependence of the grown layers has been studied as a function of the Mn supply. We find that at regular substrate temperature the incorporation of Mn into the layer is low and difficult to control. Only at a reduced substrate temperature of 650 degrees C and under N-rich growth conditions it is possible to grow homogeneous GaMnN layers if the Mn supply is below 15% of the total metal flux. The incorporation efficiency in this range is about 30%, which corresponds to a maximum Mn content in the diluted layers of about 5%. Above a critical Mn supply, GaMn3N precipitates are formed, which often extend out of the surface with a typical pyramidal structure."],["dc.identifier.doi","10.1088/0268-1242/21/9/022"],["dc.identifier.isi","000240123200023"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29725"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","1361-6641"],["dc.relation.issn","0268-1242"],["dc.title","Mn incorporation in GaN thin layers grown by molecular-beam epitaxy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","51"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Annalen der Physik"],["dc.bibliographiccitation.lastpage","61"],["dc.bibliographiccitation.volume","523"],["dc.contributor.author","Cantarero, A."],["dc.contributor.author","Cros, A."],["dc.contributor.author","Garro, N."],["dc.contributor.author","Gomez-Gomez, M. I."],["dc.contributor.author","Garcia-Cristobal, A."],["dc.contributor.author","de Lima, M. M., Jr."],["dc.contributor.author","Daudin, B."],["dc.contributor.author","Rizzi, Angela"],["dc.contributor.author","Denker, C."],["dc.contributor.author","Malindretos, Joerg"],["dc.date.accessioned","2018-11-07T09:00:41Z"],["dc.date.available","2018-11-07T09:00:41Z"],["dc.date.issued","2011"],["dc.description.abstract","In this paper we review some recent results on the optical properties of nitride nanostructures, in particular on GaN quantum dots (QDs) and InN nanocolumns (NCs). First, we will give a brief introduction on the particularities of vibrational modes of wurtzite. The GaN QDs, embedded in AlN, were grown by molecular beam epitaxy (MBE) in the Stransky-Krastanov mode on c-and a-plane 6H-SiC. We have studied the optical properties by means of photoluminescence (PL) and performed Raman scattering measurements to analyze the strain relaxation in the dots and the barrier, the effect of the internal electric fields, and the influence of specific growth parameters, like the influence of capping or the spacer on the relaxation of the QDs. A theoretical model, based on continuous elastic theory, were developed to interpret the Raman scattering results. On the other hand, InN NCs have been grown by MBE in the vapor-liquid-solid mode using Au as a catalyst. The nanocolumns have different morphology depending on the growth conditions. The optical properties can be correlated to the morphology of the samples and the best growth conditions can be selected. We observe, from the analysis of the Raman data in InN NCs, the existence of two space regions contributing to the scattering: the surface and the inner region. From the inner region, uncoupled phonon modes are clearly observed, showing the high crystal quality and the complete relaxation of the NCs (no strain). The observation of a LO-phonon-plasmon couple in the same spectra is a fingerprint of the accumulation layer predicted at the surface of the nanocolumns. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim"],["dc.identifier.doi","10.1002/andp.201000107"],["dc.identifier.isi","000285931500003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24233"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1521-3889"],["dc.relation.issn","0003-3804"],["dc.title","Optical properties of nitride nanostructures"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","864"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","physica status solidi (RRL) - Rapid Research Letters"],["dc.bibliographiccitation.lastpage","867"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Gomez-Gomez, M. I."],["dc.contributor.author","Garro, N."],["dc.contributor.author","Segura-Ruiz, J."],["dc.contributor.author","Martinez-Criado, G."],["dc.contributor.author","Chu, M. H."],["dc.contributor.author","Cantarero, A."],["dc.contributor.author","Denker, C."],["dc.contributor.author","Malindretos, Joerg"],["dc.contributor.author","Rizzi, Angela"],["dc.date.accessioned","2018-11-07T09:18:55Z"],["dc.date.available","2018-11-07T09:18:55Z"],["dc.date.issued","2013"],["dc.description.abstract","The radial alloy distribution of In-x Ga1-xN nanowires grown by plasma-assisted molecular beam epitaxy has been investigated by three different techniques with nanometric spatial resolution and capability to study single nanowires. Energy-dispersive X-ray spectroscopy radial line-scans revealed a gradient in the alloy composition of individual nanowires. Resonant Raman scattering and spatially resolved X-ray diffraction showed the existence of three distinctive regions with different alloy composition. The combination of the three techniques provides robust evidence of the spontaneous formation of a core-shell structure with a thin Ga-richer shell wrapping an In-rich core at the bottom part of the nanowires. This composition-modulated nanostructure offers an attractive way to explore new device concepts in fully epitaxial nanowire-based solar cells. ((c) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)"],["dc.identifier.doi","10.1002/pssr.201307244"],["dc.identifier.isi","000328484500018"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28515"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1862-6270"],["dc.relation.issn","1862-6254"],["dc.title","Radial composition of single InGaN nanowires: a combined study by EDX, Raman spectroscopy, and X-ray diffraction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","UNSP 053045"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","New Journal of Physics"],["dc.bibliographiccitation.volume","15"],["dc.contributor.affiliation","Urban, A;"],["dc.contributor.affiliation","Malindretos, J;"],["dc.contributor.affiliation","Klein-Wiele, J-H;"],["dc.contributor.affiliation","Simon, P;"],["dc.contributor.affiliation","Rizzi, A;"],["dc.contributor.author","Urban, Arne"],["dc.contributor.author","Malindretos, Joerg"],["dc.contributor.author","Klein-Wiele, J-H"],["dc.contributor.author","Simon, P."],["dc.contributor.author","Rizzi, Angela"],["dc.date.accessioned","2018-11-07T09:24:33Z"],["dc.date.available","2018-11-07T09:24:33Z"],["dc.date.issued","2013"],["dc.date.updated","2022-02-10T10:13:19Z"],["dc.description.abstract","Selective area growth of GaN nanocolumns (NCs) by molecular beam epitaxy on laser ablated pre-patterned GaN(0001) templates is shown to provide regular arrays of Ga-polar NCs. The Ga diffusion-assisted growth mechanism is analyzed and the experiments suggest that the effective growth conditions vary with the height of the NCs due to Ga diffusion on the mask and the NC sidewalls, ranging from N-rich up to stoichiometry. The obtained morphology with semipolar facets at the tip is discussed within the framework of equilibrium thermodynamics, which provides a consistent picture also for the growth of N-polar NCs with flat tips. The structural investigation reveals almost defect-free semipolar {1 (1) over bar 02} GaN facets at the top of the NCs, which is known to be a promising way of producing templates for nanoscale semipolar GaN-based heterostructures. Almost no polarization discontinuity is expected for InxGa1-xN/GaN interfaces on such facets."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2013"],["dc.identifier.doi","10.1088/1367-2630/15/5/053045"],["dc.identifier.eissn","1367-2630"],["dc.identifier.fs","599188"],["dc.identifier.isi","000319656300003"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9122"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29854"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.oa","gold"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","IOP Publishing"],["dc.relation","info:eu-repo/grantAgreement/EC/FP7/265073/EU//NANOWIRING"],["dc.relation.issn","1367-2630"],["dc.relation.orgunit","Fakultät für Physik"],["dc.rights","CC BY 3.0"],["dc.rights.uri","http://creativecommons.org/licenses/by/3.0/"],["dc.title","Ga-polar GaN nanocolumn arrays with semipolar faceted tips"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","063504"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Journal of Applied Physics"],["dc.bibliographiccitation.volume","101"],["dc.contributor.author","Zenneck, J."],["dc.contributor.author","Niermann, T."],["dc.contributor.author","Mai, D. D."],["dc.contributor.author","Roever, Martin"],["dc.contributor.author","Kocan, M."],["dc.contributor.author","Malindretos, Joerg"],["dc.contributor.author","Seibt, M."],["dc.contributor.author","Rizzi, Angela"],["dc.contributor.author","Kaluza, N."],["dc.contributor.author","Hardtdegen, H."],["dc.date.accessioned","2018-11-07T11:04:08Z"],["dc.date.available","2018-11-07T11:04:08Z"],["dc.date.issued","2007"],["dc.description.abstract","We report on a characteristic photoluminescence feature of the substitutional Mn in high quality GaMnN layers. The lattice site was identified using atom localization by channeling enhanced microanalysis with a transmission electron microscope. It shows that 96.5%+/- 5.0% of the Mn atoms are incorporated on the substitutional Ga site. In photoluminescence a feature appears at 1.41 eV with a phonon sideband related to the GaN matrix. The temperature evolution is characteristic of an intra-atomic transition and it is assigned to the internal transition (5)E ->(5)T(2) of the Mn(3+) ion. The assignment is supported by absorption experiments. The persistence of the clear PL signal up to about 1% Mn concentration is proposed to be a fingerprint of high quality diluted GaMnN. (c) 2007 American Institute of Physics."],["dc.identifier.doi","10.1063/1.2710342"],["dc.identifier.isi","000245317700025"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/51765"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Inst Physics"],["dc.relation.issn","0021-8979"],["dc.title","Intra-atomic photoluminescence at 1.41 eV of substitutional Mn in GaMnN of high optical quality"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","125319"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","PHYSICAL REVIEW B"],["dc.bibliographiccitation.volume","82"],["dc.contributor.author","Segura-Ruiz, J."],["dc.contributor.author","Molina-Sanchez, A."],["dc.contributor.author","Garro, N."],["dc.contributor.author","Garcia-Cristobal, A."],["dc.contributor.author","Cantarero, A."],["dc.contributor.author","Iikawa, F."],["dc.contributor.author","Denker, C."],["dc.contributor.author","Malindretos, Joerg"],["dc.contributor.author","Rizzi, Angela"],["dc.date.accessioned","2018-11-07T08:39:08Z"],["dc.date.available","2018-11-07T08:39:08Z"],["dc.date.issued","2010"],["dc.description.abstract","Photoluminescence excitation (PLE) spectra have been measured for a set of self-assembled InN nanowires (NWs) and a high-crystalline quality InN layer grown by molecular-beam epitaxy. The PLE experimental lineshapes have been reproduced by a self-consistent calculation of the absorption in a cylindrical InN NW. The differences in the PLE spectra can be accounted for the inhomogeneous electron distribution within the NWs caused by a bulk donor concentration (N(D)(+)) and a two-dimensional density of ionized surface states (N(ss)(+)). For NW radii larger than 30 nm, N(D)(+) and N(ss)(+) modify the absorption edge and the lineshape, respectively, and can be determined from the comparison with the experimental data."],["dc.identifier.doi","10.1103/PhysRevB.82.125319"],["dc.identifier.isi","000282008800002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/18918"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physical Soc"],["dc.relation.issn","1098-0121"],["dc.title","Inhomogeneous free-electron distribution in InN nanowires: Photoluminescence excitation experiments"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1162"],["dc.bibliographiccitation.issue","9-12"],["dc.bibliographiccitation.journal","Journal of Magnetism and Magnetic Materials"],["dc.bibliographiccitation.lastpage","1166"],["dc.bibliographiccitation.volume","322"],["dc.contributor.author","Ney, A."],["dc.contributor.author","Kammermeier, T."],["dc.contributor.author","Ollefs, K."],["dc.contributor.author","Ney, V."],["dc.contributor.author","Ye, S."],["dc.contributor.author","Dhar, S."],["dc.contributor.author","Plothe, Klaus-Dieter"],["dc.contributor.author","Roever, Martin"],["dc.contributor.author","Malindretos, Joerg"],["dc.contributor.author","Rizzi, Angela"],["dc.contributor.author","Wilhelm, F."],["dc.contributor.author","Rogalev, A."],["dc.date.accessioned","2018-11-07T08:43:38Z"],["dc.date.available","2018-11-07T08:43:38Z"],["dc.date.issued","2010"],["dc.description.abstract","Element specific X-ray linear dichroism (XLD), X-ray magnetic circular dichroism (XMCD) at the Ga K- and Ga and Gd L-3-edges and magnetic resonance measurements have been carried out on Gd:GaN grown by molecular beam epitaxy with different Gd concentrations. XMCD studies at the Ga K-edge reveal only a very weak magnetic polarization, which is too small to account for the colossal moments reported before by SQUID. In the dilute limit we can show by XLD that the majority of the Gd dopant atoms go to substitutional Ga sites. XMCD studies demonstrate that the Gd sublattice behaves paramagnetic which is in contrast to integral SQUID measurements. The absence of ferromagnetic order at room temperature is corroborated by magnetic resonance studies. First signatures of phase separation are visible. At higher Gd concentrations phase separation is found by XLD. In such samples ferromagnetic-like order is consistently found by SQUID, XMCD and magnetic resonance which is characteristic for a blocked superparamagnetic ensemble. In turn, phase separated ferromagnetic Gd/GdN clusters cannot account for magnetic order observed at and above 300 K by SQUID. (C) 2009 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.jmmm.2009.06.033"],["dc.identifier.isi","000275746100033"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/20015"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.publisher.place","Amsterdam"],["dc.relation.conference","4th Joint European Magnetic Symposia (JEMS 08)"],["dc.relation.eventlocation","Dublin, IRELAND"],["dc.relation.issn","1873-4766"],["dc.relation.issn","0304-8853"],["dc.title","Gd-doped GaN studied with element specificity: Very small polarization of Ga, paramagnetism of Gd and the formation of magnetic clusters"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]