Tuning the electronic and magnetic properties of lizardite clay by chemical substitution

First-principles calculations are performed to study the structural, electronic and magnetic properties of lizardite clay, Mg₃(Si₂O₅)(OH)₄, by two types of chemical substitutions. The Mg²⁺ atom and the (OH)⁻ group are substituted by alkali/transition/post-transition metal/metalloid/nonmetal atoms and halogens, respectively. A detailed analysis was performed based on the structural, parameter, energy band and density of states calculations. Our results and a comparative study of the systems exhibit the versatility of the physical characteristics of lizardite upon chemical modifications. The above modifications, e.g. the band-gap and the magnetic characteristic, are essential for tuning the physical characteristics of the mineral clay which could modify drastically the transport properties. In particular, we propose that the Ni-substituted lizardite is a promising candidate for a spin filter in spintronic applications.