{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,28]],"date-time":"2026-10-28T19:06:57Z","timestamp":1793214417431,"version":"4.5.0"},"reference-count":78,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T00:00:00Z","timestamp":1790726400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T00:00:00Z","timestamp":1790726400000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["advanced.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Advanced Science"],"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>Phase Change Materials (PCMs) can be rapidly and reversibly switched between their amorphous and crystalline state; a transition that is accompanied by a pronounced change of optoelectronic properties. Here, progress is reviewed to explain these property changes, focusing on advances by atom probe tomography (APT). This technique classifies bonding by providing two crucial bonding descriptors. Most important is the Probability of Multiple Events (PME), which is related to the likelihood that more than one ion is dislodged per successful laser pulse in laser\u2010assisted field evaporation. Crystalline PCMs are characterized by a PME above 55%, not found for metals or iono\u2010covalent solids. This confirms that crystalline PCMs employ a unique bonding mechanism coined metavalent bonding (MVB). While crystalline PCMs employ MVB, amorphous PCMs behave as covalent solids characterized by a much lower PME. PCMs thus change their bonding upon crystallization, consistent with quantum\u2010chemical calculations of bonding. Crystalline solids with a high PME lie in a narrow conductivity range between metals and iono\u2010covalent solids, indicative for a competition between electron localization and delocalization. A map quantifying chemical bonding locates metavalent solids in a region where approximately one electron is shared between adjacent atoms and bonding is not too ionic. This quantum chemical bonding map is now used to find and explain property trends relevant for PCMs in various application domains.<\/jats:p>","DOI":"10.1002\/advs.202600082","type":"journal-article","created":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T08:19:42Z","timestamp":1790756382000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Understanding and Designing Phase Change Materials: Insights From Atom Probe Tomography"],"prefix":"10.1002","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-9970-5155","authenticated-orcid":false,"given":"Jan","family":"K\u00f6ttgen","sequence":"first","affiliation":[{"name":"Institute of Physics IA RWTH Aachen University  Aachen Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0169-6110","authenticated-orcid":false,"given":"Nils von den","family":"Driesch","sequence":"additional","affiliation":[{"name":"Peter\u2010Gr\u00fcnberg\u2010Institute \u2013 JARA\u2010Institute Energy Efficient Information Technology (PGI\u201010) Wilhelm\u2010Johnen\u2010Stra\u00dfe  J\u00fclich Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3394-0707","authenticated-orcid":false,"given":"Alexander","family":"Pawlis","sequence":"additional","affiliation":[{"name":"Peter\u2010Gr\u00fcnberg\u2010Institute \u2013 JARA\u2010Institute Energy Efficient Information Technology (PGI\u201010) Wilhelm\u2010Johnen\u2010Stra\u00dfe  J\u00fclich Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1498-1025","authenticated-orcid":false,"given":"Matthias","family":"Wuttig","sequence":"additional","affiliation":[{"name":"Institute of Physics IA RWTH Aachen University  Aachen Germany"},{"name":"Peter\u2010Gr\u00fcnberg\u2010Institute \u2013 JARA\u2010Institute Energy Efficient Information Technology (PGI\u201010) Wilhelm\u2010Johnen\u2010Stra\u00dfe  J\u00fclich Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,9,30]]},"reference":[{"key":"e_1_2_16_2_1","doi-asserted-by":"publisher","DOI":"10.1038\/nmat2009"},{"key":"e_1_2_16_3_1","doi-asserted-by":"publisher","DOI":"10.1021\/cr900040x"},{"key":"e_1_2_16_4_1","doi-asserted-by":"publisher","DOI":"10.1557\/S0883769400036368"},{"key":"e_1_2_16_5_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.aao3212"},{"key":"e_1_2_16_6_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.1221561"},{"key":"e_1_2_16_7_1","doi-asserted-by":"crossref","unstructured":"R.Bez \u201cChalcogenide PCM: A Memory Technology for Next Decade \u201d inIEEE International Electron Devices Meeting(IEEE 2009) https:\/\/doi.org\/10.1109\/IEDM.2009.5424415.","DOI":"10.1109\/IEDM.2009.5424415"},{"key":"e_1_2_16_8_1","doi-asserted-by":"publisher","DOI":"10.1116\/1.3301579"},{"key":"e_1_2_16_9_1","first-page":"465","volume-title":"Phase\u2010change Materials for Non\u2010volatile Photonic Applications","author":"Wuttig M.","year":"2017"},{"key":"e_1_2_16_10_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41565\u2010020\u20100655\u2010z"},{"key":"e_1_2_16_11_1","doi-asserted-by":"publisher","DOI":"10.1080\/23746149.2016.1259585"},{"key":"e_1_2_16_12_1","doi-asserted-by":"publisher","DOI":"10.1038\/nphoton.2015.247"},{"key":"e_1_2_16_13_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.21.1450"},{"key":"e_1_2_16_14_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.1653653"},{"key":"e_1_2_16_15_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.97617"},{"key":"e_1_2_16_16_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.348620"},{"key":"e_1_2_16_17_1","doi-asserted-by":"publisher","DOI":"10.1147\/rd.524.0465"},{"key":"e_1_2_16_18_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41586\u2010024\u201007230\u20105"},{"key":"e_1_2_16_19_1","doi-asserted-by":"publisher","DOI":"10.1021\/ic051677w"},{"key":"e_1_2_16_20_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevB.73.045210"},{"key":"e_1_2_16_21_1","doi-asserted-by":"publisher","DOI":"10.1143\/JJAP.42.863"},{"issue":"8","key":"e_1_2_16_22_1","doi-asserted-by":"crossref","DOI":"10.1063\/1.1868860","article-title":"Phase\u2010Change Recording Materials With a Growth\u2010Dominated Crystallization Mechanism: A Materials Overview","volume":"97","author":"Pieterson L.","year":"2005","journal-title":"Journal of Applied Physics"},{"key":"e_1_2_16_23_1","doi-asserted-by":"publisher","DOI":"10.1038\/nmat1215"},{"issue":"1","key":"e_1_2_16_24_1","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1038\/nmat1539","article-title":"Unravelling the Interplay of Local Structure and Physical Properties in Phase\u2010Change Materials","volume":"5","author":"We\u0142nic W.","year":"2006","journal-title":"Nature Materials"},{"issue":"8","key":"e_1_2_16_25_1","doi-asserted-by":"crossref","DOI":"10.1103\/PhysRevB.81.081204","article-title":"Bonding Origin of Optical Contrast in Phase\u2010Change Memory Materials","volume":"81","author":"Huang B.","year":"2010","journal-title":"Physical Review B"},{"key":"e_1_2_16_26_1","doi-asserted-by":"publisher","DOI":"10.1002\/adma.201908302"},{"key":"e_1_2_16_27_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.85.1950"},{"key":"e_1_2_16_28_1","doi-asserted-by":"publisher","DOI":"10.1088\/1361\u20106463\/ab7e66"},{"key":"e_1_2_16_29_1","first-page":"727","article-title":"Peierls Instabilities in Covalent Structures I Electronic Structure, Cohesion and the Z = 8 \u2013 N rule","volume":"77","author":"Gaspard J.\u2010P.","year":"1998","journal-title":"Philosophical Magazine B"},{"key":"e_1_2_16_30_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41563\u2010018\u20100110\u20109"},{"key":"e_1_2_16_31_1","doi-asserted-by":"publisher","DOI":"10.1088\/0953-8984\/21\/25\/255501"},{"issue":"23","key":"e_1_2_16_32_1","doi-asserted-by":"crossref","DOI":"10.1103\/PhysRevB.76.235201","article-title":"Structural Phase Transitions on the Nanoscale: The Crucial Pattern in the Phase\u2010Change Materials Ge2Sb2Te5 and GeTe","volume":"76","author":"Akola J.","year":"2007","journal-title":"Physical Review B"},{"key":"e_1_2_16_33_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41578\u2010018\u20100076\u2010x"},{"key":"e_1_2_16_34_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41928\u2010023\u201001030\u2010x"},{"key":"e_1_2_16_35_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201404223"},{"key":"e_1_2_16_36_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevB.8.660"},{"issue":"1","key":"e_1_2_16_37_1","doi-asserted-by":"crossref","first-page":"8688","DOI":"10.1038\/s41467-025-63732-4","article-title":"Full\u2010cycle Device\u2010Scale Simulations of Memory Materials With a Tailored Atomic\u2010Cluster\u2010Expansion Potential","volume":"16","author":"Zhou Y.","year":"2025","journal-title":"Nature Communications"},{"key":"e_1_2_16_38_1","volume-title":"The Nature of the Chemical Bond and the Structure of Molecules and Crystals: An Introduction to Modern Structural Chemistry","author":"Pauling L.","year":"1960"},{"key":"e_1_2_16_39_1","doi-asserted-by":"publisher","DOI":"10.1038\/nmat2226"},{"key":"e_1_2_16_40_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevB.95.094111"},{"key":"e_1_2_16_41_1","doi-asserted-by":"publisher","DOI":"10.1002\/adma.201803777"},{"key":"e_1_2_16_42_1","doi-asserted-by":"publisher","DOI":"10.1126\/sciadv.ade0828"},{"key":"e_1_2_16_43_1","first-page":"1706735","volume-title":"Unique Bond Breaking in Crystalline Phase Change Materials and the Quest for Metavalent Bonding","author":"Zhu M.","year":"2018"},{"key":"e_1_2_16_44_1","doi-asserted-by":"publisher","DOI":"10.1039\/C6RA04656H"},{"key":"e_1_2_16_45_1","doi-asserted-by":"publisher","DOI":"10.1021\/acs.jpcc.1c00718"},{"issue":"15","key":"e_1_2_16_46_1","doi-asserted-by":"crossref","DOI":"10.1063\/1.4964760","article-title":"Domain Overlap Matrices From Plane\u2010Wave\u2010Based Methods of Electronic Structure Calculation","volume":"145","author":"Golub P.","year":"2016","journal-title":"The Journal of Chemical Physics"},{"key":"e_1_2_16_47_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cpc.2013.10.026"},{"key":"e_1_2_16_48_1","doi-asserted-by":"publisher","DOI":"10.1002\/adma.201806280"},{"key":"e_1_2_16_49_1","doi-asserted-by":"publisher","DOI":"10.1002\/adma.202208485"},{"issue":"47","key":"e_1_2_16_50_1","doi-asserted-by":"crossref","DOI":"10.1126\/sciadv.ade0828","article-title":"Classification of Properties and Their Relation to Chemical Bonding: Essential Steps Toward the Inverse Design of Functional Materials","volume":"8","author":"Sch\u00f6n C.\u2010F.","year":"2023","journal-title":"Science Advances"},{"key":"e_1_2_16_51_1","doi-asserted-by":"publisher","DOI":"10.1002\/adma.202102356"},{"key":"e_1_2_16_52_1","doi-asserted-by":"publisher","DOI":"10.1002\/adma.202403046"},{"key":"e_1_2_16_53_1","first-page":"2405294121","volume-title":"Reply to Lee and Elliott: Changes of Bonding Upon Crystallization in Phase Change Materials","author":"Raty J. Y.","year":"2024"},{"key":"e_1_2_16_54_1","doi-asserted-by":"publisher","DOI":"10.1002\/apxr.202500005"},{"key":"e_1_2_16_55_1","first-page":"2316498121","volume-title":"Tailoring Chemical Bonds to Design Unconventional Glasses","author":"Raty J. Y.","year":"2024"},{"key":"e_1_2_16_56_1","first-page":"3841","volume-title":"The Atomic Arrangement in Glass","author":"Zachariasen W. H.","year":"1932"},{"key":"e_1_2_16_57_1","doi-asserted-by":"publisher","DOI":"10.1002\/andp.18802470905"},{"key":"e_1_2_16_58_1","doi-asserted-by":"publisher","DOI":"10.1201\/b12795"},{"key":"e_1_2_16_59_1","first-page":"237","volume-title":"Progress in Semiconductors","author":"Ioffe A.","year":"1960"},{"key":"e_1_2_16_60_1","doi-asserted-by":"publisher","DOI":"10.1002\/9780470068328.ch1"},{"key":"e_1_2_16_61_1","doi-asserted-by":"publisher","DOI":"10.1002\/pssr.202000451"},{"key":"e_1_2_16_62_1","volume-title":"Topological Chiral Semimetals: Unusual Properties as Bonding Signatures of Incipient Electron Localization","author":"Hoff F.","year":"2025"},{"key":"e_1_2_16_63_1","article-title":"Divergent Coherent Phonon Responses Across the Metal\u2010Insulator Crossover","author":"Hoff F.","year":"2026","journal-title":"arXiv"},{"key":"e_1_2_16_64_1","first-page":"116","volume-title":"Investigating Bond Rupture in Resonantly Bonded Solids by Field Evaporation of Carbon Nanotubes","author":"Raghuwanshi M.","year":"2020"},{"key":"e_1_2_16_65_1","doi-asserted-by":"publisher","DOI":"10.1002\/adma.202300836"},{"key":"e_1_2_16_66_1","doi-asserted-by":"publisher","DOI":"10.1039\/D4TC00604F"},{"key":"e_1_2_16_67_1","doi-asserted-by":"publisher","DOI":"10.1039\/D5SC02936H"},{"key":"e_1_2_16_68_1","article-title":"Metavalent or Hypervalent Bonding: Is There a Chance for Reconciliation?","volume":"11","author":"Wuttig M.","year":"2023","journal-title":"Advanced Materials"},{"key":"e_1_2_16_69_1","doi-asserted-by":"publisher","DOI":"10.1088\/1361-648X\/ad46d6"},{"key":"e_1_2_16_70_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.1696820"},{"key":"e_1_2_16_71_1","doi-asserted-by":"publisher","DOI":"10.1039\/qr9571100121"},{"key":"e_1_2_16_72_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.198708461"},{"key":"e_1_2_16_73_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467\u2010021\u201025258\u20103"},{"key":"e_1_2_16_74_1","doi-asserted-by":"publisher","DOI":"10.1002\/adfm.202002447"},{"key":"e_1_2_16_75_1","doi-asserted-by":"publisher","DOI":"10.1002\/adfm.201806181"},{"key":"e_1_2_16_76_1","doi-asserted-by":"crossref","DOI":"10.1002\/adfm.202530091","article-title":"s\u2010Orbital Mediated Metavalent Bonding Enables State\u2010of\u2010the\u2010Art n\u2010Type AgBiSe2 Thermoelectrics","volume":"36","author":"Huang B.","year":"2025","journal-title":"Advanced Functional Materials"},{"key":"e_1_2_16_77_1","doi-asserted-by":"publisher","DOI":"10.1002\/adfm.201904862"},{"key":"e_1_2_16_78_1","doi-asserted-by":"publisher","DOI":"10.1002\/smll.202508738"},{"key":"e_1_2_16_79_1","doi-asserted-by":"publisher","DOI":"10.1002\/adfm.202307681"}],"container-title":["Advanced Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/advanced.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/advs.202600082","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/advanced.onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/advs.202600082","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/advanced.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/advs.202600082","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T08:19:48Z","timestamp":1790756388000},"score":1,"resource":{"primary":{"URL":"https:\/\/advanced.onlinelibrary.wiley.com\/doi\/10.1002\/advs.202600082"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,30]]},"references-count":78,"alternative-id":["10.1002\/advs.202600082"],"URL":"https:\/\/doi.org\/10.1002\/advs.202600082","archive":["Portico"],"relation":{},"ISSN":["2198-3844","2198-3844"],"issn-type":[{"value":"2198-3844","type":"print"},{"value":"2198-3844","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,30]]},"assertion":[{"value":"2026-08-18","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-08-18","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-09-30","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e00082"}}