Ferromagnetic half levitation of LK-99-like synthetic samples  

作　　者：Kaizhen Guo Yuan Li Shuang Jia 

机构地区：[1]International Center for Quantum Materials,School of Physics,Peking University,Beijing 100871,China [2]Collaborative Innovation Center for Quantum Matter,Beijing 100871,China [3]Interdisciplinary Institute of Light-Element Quantum Materials,Research Center for Light-Element Advanced Materials,Peking University Beijing100871,China [4]CAS Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2023年第10期114-120,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant No.2021YFA1401900);the CAS Interdisciplinary Innovation Team,the strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB28000000);the National Natural Science Foundation of China(Grant Nos.12141002,12225401,and U1832214)。

摘　　要：We successfully synthesized polycrystalline LK-99-like ceramic samples with a solid-state-sintering method.Powder X-ray diffraction shows that the main contents are Pb_(10-x)Cu_(x)(PO_(4))_(6)O and Cu_(2)S,consistent with recent reports (arXiv:2307.12037;arXiv:2308.01192).In some small flaky fragments,we successfully observed“half levitation”atop a Nd_(2)Fe_(14)B magnet.Using magnetization measurements on such small pieces,as well as on a large piece which does not exhibit the half levitation,we show that the samples ubiquitously contain weak yet definitive soft ferromagnetic components.We argue that,together with the pronounced shape anisotropy of the small fragments,the soft ferromagnetism is sufficient to explain the observed half levitation in strong vertical magnetic fields.Our measurements do not indicate the presence of the Meissner effect,nor zero resistance,in our samples,leading us to believe that our samples do not exhibit superconductivity.The precise chemical composition and the physics behind the ferromagnetic component remain outstanding questions to be addressed in future research.

关 键 词：superconducting materials FERROMAGNETISM magnetization curve 

分 类 号：O511.3[一般工业技术—材料科学与工程] TQ174.1[理学—低温物理]