New Critical Impurity Density in Metal-Insulator Transition, Obtained in Various N(p)- Type Degenerate Alkali Metals, Being Just That of the Cariers, Localized in Exponential Band Tails. (I)

By basing on the same physical model and treatment method, as used in our recent works (Van Cong, 2023), we will investigate the critical impurity densities in the metal-insulator transition (MIT), obtained in various n(p)-type degenerate [Li, Na, Mg, Ca, and Sr]- alkali metals, being due to the effects of the size of donor (acceptor) d(a)-radius, , and the high d(a)-density, N, assuming that all the impurities are ionized even at T=0 K. In such n(p)-type degenerate metals, we will determine: (i)-the critical impurity density in the MIT, as that given in Eq. (8), by using an empirical Mott parameter , and (ii)-the density of electrons (holes) localized in the exponential conduction (valence)-band tails (EBT), , as that given in Eq. (26), by using our empirical Heisenberg parameter, , as given in Eq. (15), according to: for a given , with a precision of the order of , as observed in Tables 2-6. In other words, such the critical d(a)-density is just the density of electrons (holes) localized in the EBT, , respectively. By basing on the same physical model and treatment method, as used in our recent works (Van Cong, 2023), we will investigate the critical impurity densities in the metal-insulator transition (MIT), obtained in various n(p)-type degenerate [Li, Na, Mg, Ca, and Sr]- alkali metals, being due to the effects of the size of donor (acceptor) d(a)-radius, , and the high d(a)-density, N, assuming that all the impurities are ionized even at T=0 K. In such n(p)-type degenerate metals, we will determine: (i)-the critical impurity density in the MIT, as that given in Eq. (8), by using an empirical Mott parameter , and (ii)-the density of electrons (holes) localized in the exponential conduction (valence)-band tails (EBT), , as that given in Eq. (26), by using our empirical Heisenberg parameter, , as given in Eq. (15), according to: for a given , with a precision of the order of , as observed in Tables 2-6. In other words, such the critical d(a)-density is just the density of electrons (holes) localized in the EBT, , respectively.