Information recording/reproducing device

An information recording/reproducing device comprising:

• a recording layer;
• and
• a recording circuit configured to record information by generating a phase change in the recording layer while applying a voltage to the recording layer, wherein
• the recording layer comprises a compound including at least one type of cationic element, and at least one type of anionic element, at least the one type of cationic element is a transition element including a d orbital incompletely filled with electrons, and the average shortest distance between adjacent cationic elements is 0.32 nm or less, and
• the recording layer is provided with a material selected from (i) AxMyX4 (0≦x≦2.2, 1.8≦y≦3), (ii) AxMyX3 (0≦x≦1.1, 0.9≦y≦3), and (iii) AxMyX4 (0≦x≦1.1, 0.9≦y≦3), where,
• regarding (i) and (ii), A is at least one type of element selected from a group comprising Na, K, Rb, Be, Mg, Ca, Sr, Ba, Al, Ga, Mn, Fe, Co, Ni, Cu, Zn, Ge, Ag, Au, Cd, Sn, Sb, Pt, Pd, Hg, Tl, Pb, and Bi;
• and
• M is at least one type of element selected from a group comprising Al, Ga, Ti, Ge, Sn, V, Cr, Mn, Fe, Co, Ni, Nb, Ta, Mo, W, Ru, and Rh,
• regarding (iii), A is at least one type of element selected from a group comprising Mg, Ca, Sr, Al, Ga, Sb, Ti, V, Cr, Mn, Fe, Co, Rh, In, Sb, Tl, Pb, and Bi;
• and
• M is at least one type of element selected from a group comprising Al, Ga, Ti, Ge, Sn, V, Nb, Ta, Cr, Mn, Mo, W, Ir, and Os, and
• regarding (i), (ii) and (iii), X contains O or N as a chief ingredient, and contains a halogen element of 1% or more and 30% or less.