%0 Journal Article %T Super-Hydrides of Lanthanum and Yttrium: On Optimal Conditions for Achieving near Room Temperature Superconductivity %A Hans Hermann Otto %J World Journal of Condensed Matter Physics %P 22-36 %@ 2160-6927 %D 2019 %I Scientific Research Publishing %R 10.4236/wjcmp.2019.91002 %X Recently, many seminal papers deal with the syntheses, stability and superconducting properties of super-hydrides like LaH10 or YH10 under high pressure, reporting critical temperatures near room temperature. In the first run one will assume that the involved metal atoms contribute a number of 3 electrons to the pairing pool corresponding to their valence. However, another possibility may be that the cationic valence is somewhat smaller, for instance only 2.29, resulting in a nominal electron number per cation of ¦Ò0 = 0.229 ¡Ö 3/13 instead of 0.3. Then, we will have a numerical equality to the optimum hole number in the cuprate high-Tc superconductors, a number that reflects the fractal nature of electronic response in superconductors. However, if one still keeps up the oxidation state of +3 of lanthanum, one will need 13 hydrogen atoms to match the optimum ¦Ò0. Such composition may be found at the phase boundary between the observed LaH10 and LaH16 phases. Partial ionic replacement is suggested to shift the super-hydride composition into the ¦Ò0 optimum. Micro-structural phenomena such as multiple twinning and ferroelastic behavior as observed with cuprates may also influence the superconductivity of super-hydrides. Finally, epitaxial growth of super-hydrides onto a specially cut diamond substrate is proposed. %K Superconductivity %K Super-Hydride %K Clathrate %K LaH< %K sub> %K 10< %K /sub> %K YH< %K sub> %K 10< %K /sub> %K Faujasite %K High Pressure %K Optimum of Pairing Charge Carriers %K Slab Width %K Ionic Substitution %K Epitaxial Growth %K Diamond Substrate %K Fractality %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=90653