Stability of the Pd-Co-Ni-Cu-P Metallic Glasses

<jats:title>Abstract</jats:title><jats:p>Stability of Pd-Co-Ni-Cu-P metallic glass was investigated in terms of free energy using first principle cluster calculations, thermal analysis, and photoemission spectroscopy measurements. We found that the internal energy of the Pd-based metallic glasses is dominated by the electronic structure near the Fermi level. The analyses on the electronic structure and local atomic arrangements indicate that the substitution of cobalt or a hypothetical atom Co<jats:sub>0.5</jats:sub>Cu<jats:sub>0.5</jats:sub> for nickel in the Pd<jats:sub>40</jats:sub>Ni<jats:sub>40</jats:sub>P<jats:sub>20</jats:sub> metallic glass decreases the free energy of the Pd-Ni-P metallic glass by increasing entropy without altering significantly internal energy. On the basis of the idea mentioned above, we prepared Pd<jats:sub>28</jats:sub>Co<jats:sub>24</jats:sub>Ni<jats:sub>24</jats:sub>P<jats:sub>24</jats:sub>, Pd<jats:sub>25</jats:sub>Co<jats:sub>25</jats:sub>Ni<jats:sub>25</jats:sub>P<jats:sub>25</jats:sub> and Pd<jats:sub>40</jats:sub>Co<jats:sub>40/3</jats:sub>Ni<jats:sub>40/3</jats:sub>Cu<jats:sub>40/3</jats:sub>P<jats:sub>20</jats:sub> metallic glasses. These metallic glasses certainly showed the nearly highest <jats:italic>T</jats:italic><jats:sub>X</jats:sub>, which directly reflect the activation energy against crystallization, among the Pd-based metallic glasses ever reported.</jats:p>