{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/42159"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/42159","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Thermal expansion and thermal conductivity of (Ca<sub>1-x</sub>,Mg<sub>x</sub>)Zr₄(PO₄)₆ where x = 0.0-0.4","abstract":"Solid-state reaction and sol-gel processing methods were used to prepare samples of (Ca<sub>1 - X,</sub>Mg<sub>X</sub>)Zr₄(PO₄)₆(CZP-CMZP) where x = 0.0-0.4. CMZP is a member of the NaZr₂(PO₄)₃ (NZP) class of ceramics and is being investigated for heat engine applications. Linear thermal expansion was determined with a dual push rod dilatometer and axial thermal expansion by high temperature X-ray diffraction and least squares refinement. Thermal diffusivity was determined with the laser flash method and specific heat by differential scanning calorimetry. Thermal conductivity was found by the product of the thermal diffusivity, specific heat, and bulk density of each sample. Results indicate that CMZP samples exhibit very low α̅<sub>L</sub> values which become more positive as Mg²⁺ content is increased. Thermal expansion anisotropy (from room temperature to 1000°C) is significantly reduced by the addition of Mg²⁺. Samples where x = 0.4 exhibit the lowest anisotropy with α<sub>a</sub> being essentially zero (hexagonal system). The thermal conductivity of CMZP samples is very low (0.56 W/m K at 200°C). Thermal conductivity values were observed to decrease with increasing Mg²⁺ content. The materials structure and cation site selection are discussed in relation to the observed properties.","abstract_html":"Solid-state reaction and sol-gel processing methods were used to prepare samples of (Ca&lt;sub&gt;1 - X,&lt;/sub&gt;Mg&lt;sub&gt;X&lt;/sub&gt;)Zr₄(PO₄)₆(CZP-CMZP) where x = 0.0-0.4. CMZP is a member of the NaZr₂(PO₄)₃ (NZP) class of ceramics and is being investigated for heat engine applications. Linear thermal expansion was determined with a dual push rod dilatometer and axial thermal expansion by high temperature X-ray diffraction and least squares refinement. Thermal diffusivity was determined with the laser flash method and specific heat by differential scanning calorimetry. Thermal conductivity was found by the product of the thermal diffusivity, specific heat, and bulk density of each sample. Results indicate that CMZP samples exhibit very low α̅&lt;sub&gt;L&lt;/sub&gt; values which become more positive as Mg²⁺ content is increased. Thermal expansion anisotropy (from room temperature to 1000°C) is significantly reduced by the addition of Mg²⁺. Samples where x = 0.4 exhibit the lowest anisotropy with α&lt;sub&gt;a&lt;/sub&gt; being essentially zero (hexagonal system). The thermal conductivity of CMZP samples is very low (0.56 W/m K at 200°C). Thermal conductivity values were observed to decrease with increasing Mg²⁺ content. The materials structure and cation site selection are discussed in relation to the observed properties.","abstract_has_math":false,"creators":["Van Aken, Stephen Mark"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Materials Engineering","degree_department":"Materials Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1990,"date_issued":"1990","date_published":"1990","updated_at":"2026-07-22T22:20:41Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-04182009-041436"],"render_values":[{"text":"etd-04182009-041436","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/42159","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Materials Engineering"]},{"key":"dc:creator","label":"Author","values":["Van Aken, Stephen Mark"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:34:14Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:34:14Z","2009-04-18"]},{"key":"dc:date.issued","label":"Date","values":["1990"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-04182009-041436"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/42159"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Solid-state reaction and sol-gel processing methods were used to prepare samples of (Ca<sub>1 - X,</sub>Mg<sub>X</sub>)Zr₄(PO₄)₆(CZP-CMZP) where x = 0.0-0.4. CMZP is a member of the NaZr₂(PO₄)₃ (NZP) class of ceramics and is being investigated for heat engine applications. Linear thermal expansion was determined with a dual push rod dilatometer and axial thermal expansion by high temperature X-ray diffraction and least squares refinement. Thermal diffusivity was determined with the laser flash method and specific heat by differential scanning calorimetry. Thermal conductivity was found by the product of the thermal diffusivity, specific heat, and bulk density of each sample. Results indicate that CMZP samples exhibit very low α̅<sub>L</sub> values which become more positive as Mg²⁺ content is increased. Thermal expansion anisotropy (from room temperature to 1000°C) is significantly reduced by the addition of Mg²⁺. Samples where x = 0.4 exhibit the lowest anisotropy with α<sub>a</sub> being essentially zero (hexagonal system). The thermal conductivity of CMZP samples is very low (0.56 W/m K at 200°C). Thermal conductivity values were observed to decrease with increasing Mg²⁺ content. The materials structure and cation site selection are discussed in relation to the observed properties."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Thermal expansion and thermal conductivity of (Ca<sub>1-x</sub>,Mg<sub>x</sub>)Zr₄(PO₄)₆ where x = 0.0-0.4"]}]}],"canonical_facts":{"dc:contributor.department":["Materials Engineering"],"dc:creator":["Van Aken, Stephen Mark"],"dc:date.accessioned":["2014-03-14T21:34:14Z"],"dc:date.available":["2014-03-14T21:34:14Z","2009-04-18"],"dc:date.issued":["1990"],"dc:description.abstract":["Solid-state reaction and sol-gel processing methods were used to prepare samples of (Ca<sub>1 - X,</sub>Mg<sub>X</sub>)Zr₄(PO₄)₆(CZP-CMZP) where x = 0.0-0.4. CMZP is a member of the NaZr₂(PO₄)₃ (NZP) class of ceramics and is being investigated for heat engine applications. Linear thermal expansion was determined with a dual push rod dilatometer and axial thermal expansion by high temperature X-ray diffraction and least squares refinement. Thermal diffusivity was determined with the laser flash method and specific heat by differential scanning calorimetry. Thermal conductivity was found by the product of the thermal diffusivity, specific heat, and bulk density of each sample. Results indicate that CMZP samples exhibit very low α̅<sub>L</sub> values which become more positive as Mg²⁺ content is increased. Thermal expansion anisotropy (from room temperature to 1000°C) is significantly reduced by the addition of Mg²⁺. Samples where x = 0.4 exhibit the lowest anisotropy with α<sub>a</sub> being essentially zero (hexagonal system). The thermal conductivity of CMZP samples is very low (0.56 W/m K at 200°C). Thermal conductivity values were observed to decrease with increasing Mg²⁺ content. The materials structure and cation site selection are discussed in relation to the observed properties."],"dc:description.degree":["Master of Science"],"dc:format.medium":["BTD"],"dc:format.mimetype":["application/pdf"],"dc:identifier.other":["etd-04182009-041436"],"dc:identifier.uri":["http://hdl.handle.net/10919/42159"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Thermal expansion and thermal conductivity of (Ca<sub>1-x</sub>,Mg<sub>x</sub>)Zr₄(PO₄)₆ where x = 0.0-0.4"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Materials Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:41Z"}