Ferromagnetic and insulating behavior in both half magnetic levitation and non-levitation LK-99 like samples
Pinyuan Wang, Xiaoqi Liu, Jun Ge, Chengcheng Ji, Haoran Ji, Yanzhao Liu, Yiwen Ai, Gaoxing Ma, Shi‐Chao Qi, Jian Wang
Abstract
Abstract Finding materials exhibiting superconductivity at room temperature has long been one of the ultimate goals in physics and material science. Recently, room-temperature superconducting properties have been claimed in a copper substituted lead phosphate apatite (Pb 10-x Cu x (PO 4 ) 6 O, or called LK-99) (Lee et al. in J. Korean Cryst. Growth Cryst. Technol. 33:61, 2023; Lee et al. in The first room-temperature ambient-pressure superconductor, 2023; Lee et al. in Superconductor Pb 10-x Cu x (PO 4 ) 6 O showing levitation at room temperature and atmospheric pressure and mechanism, 2023). Using a similar approach, we have prepared LK-99 like samples and confirmed the half-levitation behaviors in some small specimens under the influence of a magnet at room temperature. To examine the magnetic properties of our samples, we have performed systematic magnetization measurements on the as-grown LK-99 like samples, including the half-levitated and non-levitated samples. The magnetization measurements show the coexistence of soft-ferromagnetic and diamagnetic signals in both half-levitated and non-levitated samples. The electrical transport measurements on the as-grown LK-99 like samples including both half-levitated and non-levitated samples show an insulating behavior characterized by the increasing resistivity with the decreasing temperature.