▎ 摘　　要

NOVELTY - Graphene/iron-selenium composite material having high inter-grain connectivity comprises 0.95-1.05 pts. wt. iron powder, 0.95-1.05 pts. wt. selenium powder and 0.05-0.20 pts. wt. graphene powder. USE - Used as graphene/iron-selenium composite material having high inter-grain connectivity. ADVANTAGE - The iron-selenium superconducting bulk grains have excellent connectivity, and refined grain size and improved critical transition temperature Tc and critical current density Jc; utilizes easy to obtain raw materials; and has convenient operation; improved connectivity between grains and refine the grains. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing graphene/iron-selenium composite material having high inter-grain connectivity comprising (i) mixing iron powder, selenium powder, and graphene powder in a molar ratio to form mixed raw material, where molar ratio between iron powder, selenium powder, and graphene powder is 0.95-1.05: 0.95-1.05:0.05-0.20, (ii) grinding mixed raw materials to form composite powder, (iii) tableting composite powder into tablet having diameter of 5-10 mm under a pressure of 8-10 MPa, (iv) placing pressed tablet in step (iii) in a quartz tube, vacuumizing it with a vacuum machine, then purging it with argon three times, then vacuumizing, and finally sealing the quartz tube, (v) placing quartz tube in sealed sample into the tube furnace, and then flowing argon into the tube furnace, heating and sintering, where heating rate is set to 5-10 K/minutes and 900-974 K for 24-48 hours, cooling to room temperature at a cooling rate of 5-10 K/minutes to form iron-selenium compound powder, (vi) grinding iron-selenium compound powder, press tableting, and sealing the tube, placing sample sealed with a quartz tube in tube furnace with flowing argon for sintering, where heating rate is set to 5-10 K/minutes and 600-674 K for 15-20 hours, and then cooling to room temperature at a cooling rate of 5-10 K/minutes to obtain iron-selenium superconducting block.