{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:59673"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:59673","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Rekristallisationskinetik von Phasenwechselmedien","abstract":"Phase change media are tellurium based covalently bonded alloys which exist in a meta-stable amorphous phase at room temperature. Contrary to silicon based semiconductors these materials exhibit a large property contrast between the amorphous and crystalline phase. This is employed for optical and electronic data storage where small volumes are switched between the two different phases. For the amorphization the material is locally heated above the melting temperature and successively quenched into the amorphous phase. A sufficiently long heating to temperatures above the glass transition temperature and below the melting point leads to crystallization. While for optical data storage, e.g. DVDs, a focused laser beam serves as heat source, in electronic data storage (PRAM) the material is locally heated up by a current pulse. To understand the crystallization which consists of nucleation and growth, a microscopic description of the relevant processes is needed. Of particular interest is the influence of the stoi-chiometry of the material on the mechanism of the recrystallization of submicrometer large amorphous areas. It is shown that an AgInSbTe film crystallizes radially from the crystalline rim towards the center, while in the case of (GeTe)x(Sb2Te3)y the crystallization is dominated by fast nucleation and successive growth. It is the goal of this work of understand by the investigation of these two prototype systems the cause for the two different mechanisms. The results of this work show clearly that the structure of the amorphous phase is crucial for the kinetics of the crystallization. For the alloys on the pseudobinary line a catalogue could be provided, which contains criteria which must be fulfilled for the structure of the amorphous phase. As a possible candidate, that fulfills the criteria of this catalogue, a spinel-like structure is successfully tested with the existing data from this work and the literature. It can be shown that this suggestion is in remarkable agreement with the demands of the catalogue. In order to understand the recrystallisation mechanism of AgInSbTe the nucleation of this material is examined. In can be shown that amorphous AgInSbTe films nucleate heterogeneously at a finite number of nucleation sites. The minimum crystallization time is identified with the incubation time of heterogeneous nucleation. To quantify the kinetics of the growth process an extended Kissinger’s analysis has been developed to measure the activation barrier for growth. The results show that the relevant diffusion process is well described by the Stokes-Einstein relation and the Vogel-Fulcher equation for the temperatures reached by laser heating.","abstract_html":"Phase change media are tellurium based covalently bonded alloys which exist in a meta-stable amorphous phase at room temperature. Contrary to silicon based semiconductors these materials exhibit a large property contrast between the amorphous and crystalline phase. This is employed for optical and electronic data storage where small volumes are switched between the two different phases. For the amorphization the material is locally heated above the melting temperature and successively quenched into the amorphous phase. A sufficiently long heating to temperatures above the glass transition temperature and below the melting point leads to crystallization. While for optical data storage, e.g. DVDs, a focused laser beam serves as heat source, in electronic data storage (PRAM) the material is locally heated up by a current pulse. To understand the crystallization which consists of nucleation and growth, a microscopic description of the relevant processes is needed. Of particular interest is the influence of the stoi-chiometry of the material on the mechanism of the recrystallization of submicrometer large amorphous areas. It is shown that an AgInSbTe film crystallizes radially from the crystalline rim towards the center, while in the case of (GeTe)x(Sb2Te3)y the crystallization is dominated by fast nucleation and successive growth. It is the goal of this work of understand by the investigation of these two prototype systems the cause for the two different mechanisms. The results of this work show clearly that the structure of the amorphous phase is crucial for the kinetics of the crystallization. For the alloys on the pseudobinary line a catalogue could be provided, which contains criteria which must be fulfilled for the structure of the amorphous phase. As a possible candidate, that fulfills the criteria of this catalogue, a spinel-like structure is successfully tested with the existing data from this work and the literature. It can be shown that this suggestion is in remarkable agreement with the demands of the catalogue. In order to understand the recrystallisation mechanism of AgInSbTe the nucleation of this material is examined. In can be shown that amorphous AgInSbTe films nucleate heterogeneously at a finite number of nucleation sites. The minimum crystallization time is identified with the incubation time of heterogeneous nucleation. To quantify the kinetics of the growth process an extended Kissinger’s analysis has been developed to measure the activation barrier for growth. The results show that the relevant diffusion process is well described by the Stokes-Einstein relation and the Vogel-Fulcher equation for the temperatures reached by laser heating.","abstract_has_math":false,"creators":["Ziegler, Stefan"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Wuttig, Matthias"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2005,"date_issued":"2005","date_published":"2005","updated_at":"2026-07-30T19:42:39Z","subjects":["info:eu-repo/classification/ddc/530","Optischer Speicher","Tellurlegierung","Phasenumwandlung","Rekristallisationskinetik","Physik","Phasenwechselmedien","Kinetik","Kristallisation","GST","AIST"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121436%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121436%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121436%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/59673","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Wuttig, Matthias"]},{"key":"dc:creator","label":"Author","values":["Ziegler, Stefan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2005"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-20050220"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/530","Optischer Speicher","Tellurlegierung","Phasenumwandlung","Rekristallisationskinetik","Physik","Phasenwechselmedien","Kinetik","Kristallisation","GST","AIST"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/59673","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121436%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Phase change media are tellurium based covalently bonded alloys which exist in a meta-stable amorphous phase at room temperature. Contrary to silicon based semiconductors these materials exhibit a large property contrast between the amorphous and crystalline phase. This is employed for optical and electronic data storage where small volumes are switched between the two different phases. For the amorphization the material is locally heated above the melting temperature and successively quenched into the amorphous phase. A sufficiently long heating to temperatures above the glass transition temperature and below the melting point leads to crystallization. While for optical data storage, e.g. DVDs, a focused laser beam serves as heat source, in electronic data storage (PRAM) the material is locally heated up by a current pulse. To understand the crystallization which consists of nucleation and growth, a microscopic description of the relevant processes is needed. Of particular interest is the influence of the stoi-chiometry of the material on the mechanism of the recrystallization of submicrometer large amorphous areas. It is shown that an AgInSbTe film crystallizes radially from the crystalline rim towards the center, while in the case of (GeTe)x(Sb2Te3)y the crystallization is dominated by fast nucleation and successive growth. It is the goal of this work of understand by the investigation of these two prototype systems the cause for the two different mechanisms. The results of this work show clearly that the structure of the amorphous phase is crucial for the kinetics of the crystallization. For the alloys on the pseudobinary line a catalogue could be provided, which contains criteria which must be fulfilled for the structure of the amorphous phase. As a possible candidate, that fulfills the criteria of this catalogue, a spinel-like structure is successfully tested with the existing data from this work and the literature. It can be shown that this suggestion is in remarkable agreement with the demands of the catalogue. In order to understand the recrystallisation mechanism of AgInSbTe the nucleation of this material is examined. In can be shown that amorphous AgInSbTe films nucleate heterogeneously at a finite number of nucleation sites. The minimum crystallization time is identified with the incubation time of heterogeneous nucleation. To quantify the kinetics of the growth process an extended Kissinger’s analysis has been developed to measure the activation barrier for growth. The results show that the relevant diffusion process is well described by the Stokes-Einstein relation and the Vogel-Fulcher equation for the temperatures reached by laser heating."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University VI, 165 S. : Ill., graph. Darst. (2005). = Aachen, Techn. 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While for optical data storage, e.g. DVDs, a focused laser beam serves as heat source, in electronic data storage (PRAM) the material is locally heated up by a current pulse. To understand the crystallization which consists of nucleation and growth, a microscopic description of the relevant processes is needed. Of particular interest is the influence of the stoi-chiometry of the material on the mechanism of the recrystallization of submicrometer large amorphous areas. It is shown that an AgInSbTe film crystallizes radially from the crystalline rim towards the center, while in the case of (GeTe)x(Sb2Te3)y the crystallization is dominated by fast nucleation and successive growth. It is the goal of this work of understand by the investigation of these two prototype systems the cause for the two different mechanisms. The results of this work show clearly that the structure of the amorphous phase is crucial for the kinetics of the crystallization. For the alloys on the pseudobinary line a catalogue could be provided, which contains criteria which must be fulfilled for the structure of the amorphous phase. As a possible candidate, that fulfills the criteria of this catalogue, a spinel-like structure is successfully tested with the existing data from this work and the literature. It can be shown that this suggestion is in remarkable agreement with the demands of the catalogue. In order to understand the recrystallisation mechanism of AgInSbTe the nucleation of this material is examined. In can be shown that amorphous AgInSbTe films nucleate heterogeneously at a finite number of nucleation sites. The minimum crystallization time is identified with the incubation time of heterogeneous nucleation. To quantify the kinetics of the growth process an extended Kissinger’s analysis has been developed to measure the activation barrier for growth. The results show that the relevant diffusion process is well described by the Stokes-Einstein relation and the Vogel-Fulcher equation for the temperatures reached by laser heating."],"dc:identifier":["https://publications.rwth-aachen.de/record/59673","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121436%22"],"dc:language":["ger"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-20050220"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University VI, 165 S. : Ill., graph. Darst. (2005). = Aachen, Techn. Hochsch., Diss., 2005"],"dc:subject":["info:eu-repo/classification/ddc/530","Optischer Speicher","Tellurlegierung","Phasenumwandlung","Rekristallisationskinetik","Physik","Phasenwechselmedien","Kinetik","Kristallisation","GST","AIST"],"dc:title":["Rekristallisationskinetik von Phasenwechselmedien"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:42:39Z"}