Electronic specific heats for amorphous and crystallized alloys.

Area of Science:

• Materials Science
• Condensed Matter Physics

Background:

• Low-temperature specific heat measurements are crucial for understanding material properties.
• Amorphous alloys exhibit unique characteristics compared to their crystallized counterparts.

Purpose of the Study:

• To measure and analyze the low-temperature specific heats of (Fe0.5Co0.5)72B20Si4Nb4 amorphous and crystallized alloys.
• To investigate the factors contributing to differences in specific heat between amorphous and crystallized states.

Main Methods:

• Specific heat measurements were conducted on amorphous and crystallized (Fe0.5Co0.5)72B20Si4Nb4 alloys from 1.4 to 110 K.
• Analysis involved fitting specific heat data to electronic and phonon contribution terms.

Main Results:

• Specific heats were well-described by electronic and phonon contributions for both alloy types.
• The electronic contribution to specific heat was significantly larger in the amorphous alloy compared to the crystallized alloy.
• An enhanced electronic specific heat coefficient (γ) in amorphous alloys was observed.

Conclusions:

• The increased electronic specific heat in amorphous alloys is attributed to a higher electronic density of states at the Fermi level.
• Localized 'rattler' atoms within oversized cage structures may also contribute to the enhanced electronic specific heat.
• Understanding these low-temperature properties is vital for elucidating structure-property relationships in amorphous alloys.