Bulk properties of UIr$sub 2$ and UIr$sub 3$

Conference · Mon Dec 01 04:00:00 EST 1975

OSTI ID:4145294

Brodsky, M B; Trainor, R J; Arko, A J; Culbert, H V

The electrical resistivity and magnetic susceptibility of the cubic intermetallic compounds UIr$sub 2$ (MgCu$sub 2$-type) and UIr$sub 3$ (ordered, AuCu$sub 3$-type) were measured between 2-300$sup 0$K. The susceptibility of UIr$sub 3$ is temperature independent and substantially lower than that of isoelectronic URh$sub 3$, being 0.57 vs 0.97 x 10$sup -3$ emu/mole at room temperature. The susceptibility of UIr$sub 2$ is very weakly temperature dependent above 100$sup 0$K and has a value of 1.18 x 10$sup -3$ emu/mole at room temperature. The electrical resistivities of both compounds follow power law dependences at low temperatures, of the form rho-rho$sub 0$ = AT/sup n/, with n = 1.9 for UIr$sub 2$ and n = 3.7 for UIr$sub 3$. These results indicate that UIr$sub 2$ may be a spin fluctuation compound, while UIr$sub 3$ behaves as a simple transition metal compound, with even less d-f character than URh$sub 3$ (n = 3.0). The specific heat of UIr$sub 2$ was measured between 1-4K and may be fit to C =$gamma$T + $beta$$T$$sup 3$, with a large value of $gamma$, 62.5 mJ/(mole- K$sup 2$), which is consistent with a narrow 5f band at the Fermi level. The lack of any magnetic phenomena in UIr$sub 3$ is explained by the hybridization of the 5f electrons into f-d bands, which mostly lie below the Fermi level. (auth)

• Research Organization: Argonne National Lab., Ill. (USA)
• DOE Contract Number: W-31109-ENG-38
• NSA Number: NSA-33-007812
• OSTI ID: 4145294
• Report Number(s): CONF-751209--7
• Country of Publication: United States
• Language: English

Related Subjects

*IRIDIUM ALLOYS-- MAGNETIC SUSCEPTIBILITY
*URANIUM ALLOYS-- MAGNETIC SUSCEPTIBILITY
360104* --Materials--Metals & Alloys--Physical Properties
ELECTRONIC STRUCTURE
INTERMETALLIC COMPOUNDS
LOW TEMPERATURE
MEDIUM TEMPERATURE
N50230* --Metals
Ceramics
& Other Materials--Metals & Alloys--Properties
Structure & Phase Studies
SPECIFIC HEAT
TEMPERATURE DEPENDENCE
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE