The radiation disordering method was used to investigate the features of electron states of two classes of systems with strong electron correlations: high-temperature superconductors (HTSC) and heavy-fermion (HF) systems, which, at low temperatures, have their electron states formed as a result of strong interaction of conductivity electrons with localized magnetic moments. To find out the factors leading to changes in the properties of these compounds, the effects of radiation disordering in simpler systems are first analyzed: (1) in superconducting (SC) intermetallic compounds MgB₂ and MgCNi₃; (2) in compounds with relatively low concentration of charge carriers, such as In_xBi_2-xTe₃, HgSe, pyrolytic graphite and quasicrystal (i)-AlPdRe; (3) in oxide compounds K_0.3WO₃ and Sr₂RuO₄. It was shown that, through analyzing the experimental data within the scope of simple models, a number of significant features of electron states of the initial (ordered) compounds may be defined. In the systems with carriers concentration n = 10¹⁷-10¹⁹ cm^-3, the generation of radiation defects carrying effective charge results in the Fermi level shift, being the main factor of the observed transportation properties change, while the effects of scattering on additional defects are less significant. In the HTSC and HF systems, qualitatively different disordering effects are observed. In this case, the presence of initial unique electron states formed at interaction of electrons with localized magnetic moments and responsible for the "unusual" superconductivity is a stronger factor, rather than defects doping. Crystalline order is very important for these low-temperature states existence: its loss leads to their suppression. The nature of HF states degradation at disordering depends on the value of effective mass m*: from complete suppression at m*/m_e > 100 to relatively weak changes in the properties at m*/m_e < 10. The electron system coherent decay caused by disordering, with subsequent formation of two weakly interacting subsystems, presents a radiation defect common to the HTSC and HF systems, also leading to quick suppression of superconductivity states. At loss of crystalline order in these systems, the type of interaction in them changes from collective to local, which may be regarded as a continuous phase transition - a circumstance often ignored in construction of theoretical models describing these fine quantum states.

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