{"id":28273,"date":"2012-07-31T23:47:44","date_gmt":"2012-07-31T21:47:44","guid":{"rendered":"https:\/\/icmsva.vallealto.es\/?articulos_sci=structural-and-kinetic-study-of-phase-transitions-in-laysi2o7"},"modified":"2026-04-14T11:49:06","modified_gmt":"2026-04-14T09:49:06","slug":"structural-and-kinetic-study-of-phase-transitions-in-laysi2o7","status":"publish","type":"articulos_sci","link":"https:\/\/icmsva.vallealto.es\/?articulos_sci=structural-and-kinetic-study-of-phase-transitions-in-laysi2o7","title":{"rendered":"Structural and kinetic study of phase transitions in LaYSi2O7"},"content":{"rendered":"<figure><img decoding=\"async\" src=\"https:\/\/icmsva.vallealto.es\/wp-content\/uploads\/2012\/07\/Structural-and-kinetic-study-of-phase-transitions-1.png\" alt=\"Structural and kinetic study of phase transitions in LaYSi2O7\" \/><\/figure>\n<p>Phase transitions in LaYSi <sub>2<\/sub>O <sub>7<\/sub> have been investigated as a function of temperature using XRD, NMR and TEM. Previously described empirical crystal structure guidelines based on average cation radius in rare-earth RE <sub>2<\/sub>Si <sub>2<\/sub>O <sub>7<\/sub>-type disilicates predict a stable tetragonal A-LaYSi <sub>2<\/sub>O <sub>7<\/sub> polymorph at temperatures below 1500\u00b0C. This study demonstrates that A-LaYSi <sub>2<\/sub>O <sub>7<\/sub> is not thermodynamically stable at these temperatures and suggests that guidelines based on average cation size do not accurately describe the equilibrium behaviour of this silicate system. The A to G-type polymorph transition is extremely sluggish; complete transformation requires ~250h at 1200\u00b0C, and more than 3 weeks of calcination at 1100\u00b0C. This observation is important when this type of material is used as environmental barrier coating (EBC) of advanced ceramics. Analysis of XRD and TEM data reveal complete substitution of Y and La on the rare-earth cation sites in both LaYSi <sub>2<\/sub>O <sub>7<\/sub> polymorphs, but indicate preferential site occupancies in the G-type polymorph.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Phase transitions in LaYSi 2O 7 have been investigated as a function of temperature using XRD, NMR and TEM. Previously described empirical crystal structure guidelines based on average cation radius in rare-earth RE 2Si 2O 7-type disilicates predict a stable tetragonal A-LaYSi 2O 7 polymorph at temperatures below 1500\u00b0C. This study demonstrates that A-LaYSi 2O&hellip;<\/p>\n","protected":false},"featured_media":28279,"template":"","autores":[],"grupos_de_investigacion":[147],"revistas":[1015],"anos":[893],"class_list":["post-28273","articulos_sci","type-articulos_sci","status-publish","has-post-thumbnail","hentry","grupos_de_investigacion-materiales-coloidales","revistas-journal-of-the-european-ceramic-society","anos-893","description-off"],"acf":[],"_links":{"self":[{"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=\/wp\/v2\/articulos_sci\/28273","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=\/wp\/v2\/articulos_sci"}],"about":[{"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=\/wp\/v2\/types\/articulos_sci"}],"version-history":[{"count":1,"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=\/wp\/v2\/articulos_sci\/28273\/revisions"}],"predecessor-version":[{"id":28282,"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=\/wp\/v2\/articulos_sci\/28273\/revisions\/28282"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=\/wp\/v2\/media\/28279"}],"wp:attachment":[{"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=28273"}],"wp:term":[{"taxonomy":"autores","embeddable":true,"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=%2Fwp%2Fv2%2Fautores&post=28273"},{"taxonomy":"grupos_de_investigacion","embeddable":true,"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=%2Fwp%2Fv2%2Fgrupos_de_investigacion&post=28273"},{"taxonomy":"revistas","embeddable":true,"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=%2Fwp%2Fv2%2Frevistas&post=28273"},{"taxonomy":"anos","embeddable":true,"href":"https:\/\/icmsva.vallealto.es\/index.php?rest_route=%2Fwp%2Fv2%2Fanos&post=28273"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}