A multi-value 3D crossbar array nonvolatile memory based on pure memristors Jingru Sun, Kexin Kang, Yichuang Sun, Qinghui Hong and Chunhua Wang Eur. Phys. J. Spec. Top., 231 16-17 (2022) 3119-3130 Published online: 06 May 2022 DOI: 10.1140/epjs/s11734-022-00576-9