Evidence for a coupled magnetic-crystallographic transformation in Nd5(Si0.6Ge0.4)4 -: art. no. 224429

被引：18

作者：

Magen, C ^{[1
]}

Morellon, L

Algarabel, PA

Ibarra, MR

Ritter, C

Pecharsky, AO

Gschneidner, KA

Pecharsky, VK

机构：

[1] Univ Zaragoza, Dept Fis Mat Condensada, E-50009 Zaragoza, Spain

[2] Univ Zaragoza, Inst Ciencia Mat Aragon, E-50009 Zaragoza, Spain

[3] CSIC, E-50009 Zaragoza, Spain

[4] Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France

[5] Iowa State Univ, Mat & Engn Phys Program, Ames, IA 50011 USA

[6] Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA

来源：

PHYSICAL REVIEW B | 2004年 / 70卷 / 22期

关键词：

D O I：

10.1103/PhysRevB.70.224429

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We have performed a detailed study of the magnetic and structural properties of the compound Nd-5(Si0.6Ge0.4)(4) by means of neutron powder diffraction, magnetization, linear thermal expansion, and magnetostriction experiments. A coupled magnetic and crystallographic first-order transformation from a room-temperature monoclinic Gd5Si2Ge2-type paramagnetic state to a low-temperature orthorhombic Gd5Si4-type ferromagnetic structure takes place on cooling at similar to68 K. This magnetostructural transition shifts towards higher temperatures by the application of an external magnetic field at a rate of 0.11(1) K/kOe, which is lower than the similar to0.6 to similar to0.3 K/kOe observed in the Gd-5(SixGe1-x)(4) and Tb-5(SixGe1-x)(4) compounds. The magnetostructural transformation cannot be completed in the isothermal regime by a 120 kOe magnetic field. It is suggested that the single-ion anisotropy of the Nd ions hinders the completion of the field-induced transformation. The existence of a simultaneous magnetic and crystallographic transformation in this alloy, which is in sharp contrast with other previously studied Nd-5(SixGe1-x)(4) alloys, is discussed in terms of the role of interstitial impurities in triggering and coupling/decoupling the crystallographic transition.

引用

页码：224429 / 1

页数：8

共 41 条

[1] The magnetic structures of Nd5Si4 and Nd5Ge4 [J].

Cadogan, JM ;

Ryan, DH ;

Altounian, Z ;

Wang, HB ;

Swainson, IP .

JOURNAL OF PHYSICS-CONDENSED MATTER, 2002, 14 (30) :7191-7200

[2] Making and breaking covalent bonds across the magnetic transition in the giant magnetocaloric material Gd5(Si2Ge2) [J].

Choe, W ;

Pecharsky, VK ;

Pecharsky, AO ;

Gschneidner, KA ;

Young, VG ;

Miller, GJ .

PHYSICAL REVIEW LETTERS, 2000, 84 (20) :4617-4620

[3] METALS, ALLOYS AND COMPOUNDS - HIGH PURITIES DO MAKE A DIFFERENCE [J].

GSCHNEIDNER, KA .

JOURNAL OF ALLOYS AND COMPOUNDS, 1993, 193 (1-2) :1-6

[4] The nonpareil R5(SixGe1-x)4 phases [J].

Gschneidner, KA ;

Pecharsky, VK ;

Pecharsky, AO ;

Ivtchenko, VV ;

Levin, EM .

JOURNAL OF ALLOYS AND COMPOUNDS, 2000, 303 :214-222

[5]

Huang H, 2002, AIP CONF PROC, V614, P11, DOI 10.1063/1.1472520

[6]

Ivtchenko V.V., 2000, ADV CRYOGEN ENG, V46, P405

[7]

KRYPIAKEVICH PI, 1975, DOPOV AKAD NAUK UK A, V37, P1129

[8] Magnetic correlations induced by magnetic field and temperature in Gd5Ge4 -: art. no. 214427 [J].

Levin, EM ;

Gschneidner, KA ;

Pecharsky, VK .

PHYSICAL REVIEW B, 2002, 65 (21) :1-5

[9] Magnetic-field and temperature dependencies of the electrical resistance near the magnetic and crystallographic first-order phase transition of Gd-5(Si2Ge2) [J].

Levin, EM ;

Pecharsky, VK ;

Gschneidner, KA .

PHYSICAL REVIEW B, 1999, 60 (11) :7993-7997

[10] Spontaneous generation of voltage in Gd5(SixGe4-x) during a first-order phase transition induced by temperature or magnetic -: art. no. 174110 [J].

Levin, EM ;

Pecharsky, VK ;

Gschneidner, KA .

PHYSICAL REVIEW B, 2001, 63 (17)

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