MAGNETIC CHARACTERISTICS OF PRASEODYMIUM, NEODYMIUM, AND SAMARIUM HYDRIDES

Journal Article · Mon Apr 01 04:00:00 EST 1963 · Journal of Applied Physics (U.S.)

DOI:https://doi.org/10.1063/1.1729503· OSTI ID:4630214

Kubota, Y; Wallace, W E

Magnetization-temperature data are presented for the hydrides PrH/sub 2.02/ to PrH/sub 2.71/, NdH/sub 2.02/ to NdH/sub 2.76/, and SmH /sub 1.99/ to SmH/ sub 2/85/ and for the three parent metals from 4.2to 300 deg K. Of the twelve hydrides examined only NdH/sub 2.02/ and NdH/sub 2.03/ exhibited magnetic ordering. These hydrides exhibited a Curie point at 9.5 deg K and the saturation moment measured at 4.2 deg K was 1.36 mu /sub BETA / per Nd atom. Assuming the applicability of a Brillouin function with J = 9/2 the moment extrapolated to 0 deg K is 1.51 mu s/sub BETA /. These values are considerably lower than the value for the free tripositive ion (3.27 mu /sub BETA /) or the moment observed in the paramagnetic region (3.40 mu /sub BETA /) but are in reasonably good agreement with the theoretical value (1.58 mu /sub BETA /) computed for 4.2 deg K taking into account crystal field effects. The susceptibility behavior of the four Sm hydrides studied is generally similar. The trend with temperature is in reasonably good agreement with theory that treats Sm as a free tripositive ion. Susceptibility of the Nd hydrides follows the Curie-Weiss law above about 100 deg K with the expected slope but deviates negatively from it at lower temperatures. The deviations are attributed to either incipient ferromagnetic ordering or crystal field effects or a combination of the two. The susceptibility behavior of the Pr hydrides is very unusual. The highest hydrides exhibit Curie-Weiss behavior above about 80 deg K but show positive deviations from linearity in 1// sub X/ vs T at lower temperatures. That the deviations may be due to crystal field effects is considered possible but unlikely. PrH/sub 2.03/ and PrH/sub 2.04/ exhibit essentially identical susceptibility behavior and do not follow the Curie-Weiss law. Their susceptibilities are anomalously high near room temperature, exceeding the values for the element and the saturated hydride by a factor of about five. (auth)

• Research Organization: Univ. of Pittsburgh
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-037710
• OSTI ID: 4630214
• Journal Information: Journal of Applied Physics (U.S.), Journal Name: Journal of Applied Physics (U.S.) Vol. Vol: 34; ISSN JAPIA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BRILLOUIN FUNCTION
CRYSTALS
CURIE POINT
CURIE-WEISS LAW
FERROMAGNETIC MATERIALS
MAGNETIC FIELDS
MAGNETIC MOMENTS
MAGNETISM
MEASURED VALUES
NEODYMIUM
NEODYMIUM HYDRIDES
NUMERICALS
PHYSICS
PRASEODYMIUM
PRASEODYMIUM HYDRIDES
QUANTUM MECHANICS
SAMARIUM
SAMARIUM HYDRIDES
SPIN
SUSCEPTIBILITY
TEMPERATURE