15 Result(s)

Chapter

New Ternary Magnetic Lanthanide Regenerator Materials for the Low-Temperature Stage of a Gifford-McMahon (G-M) Cryocooler

Four new alloys Er₆Ni₂Sn, Er₆Ni₂Pb, Er₆Ni₂(Sn_0.75Ga_0.25), and 50:50 Er₆Ni₂Sn/Er₃Ni have been prepared and studied as potential candidate materials for the lower temperature stage of Gifford-McMahon (G-M) cryocool...

K. A. Gschneidner Jr., V. K. Pecharsky, M. Gailloux in Cryocoolers 8 (1995)

Chapter

Processing and Testing of the Low-Temperature Stage Er₆Ni₂Sn Cryogenic Regenerator Alloy

Low temperature heat capacity measurements have shown that Er₆Ni₂Sn might be a useful low temperature, <20 K, cryocooler regenerator material. Here we report on (1) our efforts to prepare small particles for use ...

K. A. Gschneidner Jr., V. K. Pecharsky, M. G. Osborne, J. O. Moorman… in Cryocoolers 9 (1997)

Chapter

Influence of Alloying on the Behavior and Properties of Er₃Ni

A study on processing and alloying of the passive magnetic regenerator material Er₃Ni revealed that the cooling rates of the order of 10⁶ K/sec are insufficient to quench it into a glassy state. Small additions o...

V. K. Pecharsky, K. A. Gschneidner Jr., R. W. McCallum, K. W. Dennis in Cryocoolers 9 (1997)

Article

The standard state of cerium

Based on two studies carried out about 20 years apart, it was found that the double close-packed hexagonal βCe phase slowly transformed to the face-centered cubic γCe phase at room temperature and ambient pres...

K. A. Gschneidner Jr., V. K. Pecharsky in Journal of Phase Equilibria (1999)

Chapter

Magnetocaloric Effect in GdAl₂ and Nd₂Fe₁₇

The magnetocaloric properties of GdAl₂ and Nd₂Fe₁₇ have been determined by three methods: (1) measured directly in pulsed (∼0.2 s duration) and semi-static magnetic fields; (2) calculated from the heat capacity m...

S. Yu. Dan’kov, V. V. Ivtchenko… in Advances in Cryogenic Engineering Material… (2000)

Chapter

Magnetothermal Properties of Dy₅(Si_xGe_1−x)₄ Alloys

A study of a series of Dy₅(Si_xGe_1−x)4 alloys using dc and ac magnetic susceptibility, magnetization, heat capacity, and x-ray powder diffraction techniques revealed that the variation of the magnetic properties a...

V. V. Ivtchenko, V. K. Pecharsky… in Advances in Cryogenic Engineering Material… (2000)

Chapter

Ductile, High Heat Capacity, Magnetic Regenerator Alloys for the 10 to 80 K Temperature Range

New erbium-based regenerator materials have been developed as a replacement for lead in low temperature cryocoolers. These alloys have volumetric heat capacities which are 20 to 185% larger than that of lead f...

K. A. Gschneidner Jr., A. O. Pecharsky, V. K. Pecharsky in Cryocoolers 11 (2002)

Chapter

Manufacturing Considerations for Rare Earth Powders Used in Cryocooler and Magnetic Refrigerator Applications

The high chemical reactivity and oxygen affinity of the rare earth metals make them especially difficult to produce and maintain as high purity powders. From the initial oxide reduction through bulk melt prepa...

S. A. Miller, J. D. Nicholson, K. A. Gschneidner Jr., A. O. Pecharsky… in Cryocoolers 11 (2002)

Chapter

New Regenerator Materials for Use in Pulse Tube Coolers

A two-stage pulse tube cooler driven by a linear compressor is being developed to provide cooling at 20 K. The first stage of the cooler will have the conventional stainless steel screen regenerator matrix. Th...

A. Kashani, B. P. M. Helvensteijn, P. Kittel, K. A. Gschneidner Jr.… in Cryocoolers 11 (2002)

Chapter

Magnetothermal Properties of Polycrystalline Gd₂In

The magnetic, thermodynamic and magnetocaloric properties of Gd₂In have been investigated as a part of a continuing study of novel lanthanide-based materials in order to improve our knowledge about the nature of ...

M. I. Ilyn, A. M. Tishin, K. A. Gschneidner Jr., V. K. Pecharsky… in Cryocoolers 11 (2002)

Chapter

Low Temperature Cryocooler Regenerator Materials

There are four importantfactorswhich influence the magnitude of the magnetic heat capacity near the magnetic ordering transition temperature. These include the theoretical magnetic entropy, the deGennes factor...

K. A. Gschneidner Jr., A. O. Pecharsky, V. K. Pecharsky in Cryocoolers 12 (2003)

Chapter and Conference Paper

Development of New Cryocooler Regenerator Materials — Ductile Intermetallic Compounds

The volumetric heat capacities of a number of binary and ternary Er- and Tm-based intermetallic compounds, which exhibited substantial ductilities, were measured from ∼3 to ∼350 K. They have the RM stoichiomet...

K. A. Gschneidner Jr., A. O. Pecharsky, V. K. Pecharsky in Cryocoolers 13 (2005)

Chapter

Magnetocaloric Effect Associated with Magnetostructural Transitions

V. K. Pecharsky, K. A. Gschneidner Jr. in Magnetism and Structure in Functional Materials (2005)

Article

Do**-induced valence change in Yb₅Ge_4 − x (Sb, Ga) _x : (x ≤ 1)

Following our earlier observation that the ytterbium valence distribution in Yb₅Ge_4 − x Si _x was independent of x, we use ¹⁷⁰Yb Mössbauer spectroscopy to follow ...

D. H. Ryan, N. R. Lee-Hone, J. M. Cadogan, K. Ahn… in Hyperfine Interactions (2012)

Chapter and Conference Paper

Do**-induced valence change in Yb₅Ge_4 − x (Sb, Ga) _x : (x ≤ 1)

Following our earlier observation that the ytterbium valence distribution in Yb₅Ge_4 − x Si _x was independent of x, we use ¹⁷⁰Yb Mössbauer spectroscopy to follow the Yb valen...

D. H. Ryan, N. R. Lee-Hone, J. M. Cadogan, K. Ahn, V. K. Pecharsky… in ICAME 2011 (2013)