{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"2c6b4d16041950bbab0955de02f34498d62dde30b669f78512f1a1a1b49b06b4","created":"2026-10-03T07:18:00Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"69089246cc073caca76dcd4aaba101bb7b079901c117a1a0238ac9f57b5e8d6f","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"cm.multiferroics.room-temperature-strong-coupling","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"BiFeO3 is magnetic and ferroelectric at room temperature but has almost no net magnetization, while materials with strong coupling between the two orders work only at low temperature. No single material yet combines both at room temperature.","posed_since":"","precise":"Identify a single-phase compound with ferroelectric polarization above about $3e3\\ \\mathrm{statC}/\\mathrm{cm}^{2}$ and net magnetization above $10\\ \\mathrm{emu}/\\mathrm{cm}^{3}$ at $T = 300\\ \\mathrm{K}$, in which an electric field deterministically reverses (or rotates by $90\\ \\text{degrees}$) the magnetization. An answer is a material with measured P, $M$ and demonstrated electric-field reversal of M at $300\\ \\mathrm{K}$ without a ferromagnetic overlayer.","problem_ref":null,"references":"","settled_by":"Synthesis and measurement of a single-phase compound showing 300 K polarization and magnetization hysteresis plus electric-field-driven magnetization reversal imaged by XMCD-PEEM or magnetic force microscopy.","status_note":"Deterministic switching at $300\\,\\mathrm{K}$ so far uses BiFeO3 coupled to a ferromagnetic layer (Heron et al., Nature 2014).","title":"A single-phase room-temperature multiferroic with strong magnetoelectric coupling","topic_ref":"87053ab66198285a41dc47ad97182dd67de190ae0a1fe915cd27ab2466d618c1"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"0e680aca51fd9a8975b25f9fede761b6f8f047a2098feb8a511013e11c28bedb","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"012eab1ac76caa4579c1d4fc72d3266a5e048a29c12d39e50849a12b0bdef346","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"jmz3LeTLGbsGWE2gSEkrkH3bRmu1Ty12VA2Rb281RlbMJsywnf3x28jvfqQwvw9c1Dd0iT7_AmYnE52pRLO5Aw"},"schema":"pubphys.envelope/1"},"record_hash":"0e680aca51fd9a8975b25f9fede761b6f8f047a2098feb8a511013e11c28bedb","leaf_index":1105}