magnetocaloric effect and magnetic field-induced martensitic transformation in metamagnetic shape...
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Magnetocaloric effect and magnetic field-inducedmartensitic transformation in metamagnetic shape
memory alloys
Pablo Alvarez-Alonso
C.O. Aguilar-Ortiz, J. López-García, J.P. Camarillo, D. Salazar, P. Lazpita,H. Flores-Zuñiga, and V.A. Cherneko
Energy Materials NanotechnologySan Sebastián (2015)
Introduction Measurement of ∆Tad Results Conclusions
Collaboration
BCMaterials and University of the Basque Country
JavierLópez-García
Dr. Daniel SalazarJaramillo
Dr. PatriciaLazpita
Dr. VolodymyrChernenko
Instituto Potosino de Investigación Científica y Tecnológica (Mexico)
Juan PabloCamarillo
Christian O.Aguilar-Ortiz
Dr. HoracioFlores-Zuñiga
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Outline
1 Introduction
2 Direct measurement of Adiabatic Temperature Change
3 ResultsNi-Mn-In bulk alloysNi-Mn-Sn Ribbons
4 Conclusions
Introduction Measurement of ∆Tad Results Conclusions
Shape Memory Alloys
Shape Memory Alloys
Martensitic Transformation (First-order)Difussionless phase transition by nucleation
Austenite: CubicMartensite: Low symmetry
Variants↓
Equivalent crystal structures with differentorientations
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Introduction Measurement of ∆Tad Results Conclusions
Metamagnetic shape memory alloys
Metamagnetic Shape Memory Alloys
Ni-Mn-X Heusler alloys(X = In, Sn, Sb, . . . )
↓Field-induced reverse MT
↓Metamagnetic Shape Memory Effect −→
R. Kainuma et al. Nature 439 (2006) 957-960
A. Planes et al. J. Phys.: Condens. Matter. 21 (2009) 2332012 / 17
Introduction Measurement of ∆Tad Results Conclusions
Magnetocaloric Effect
Magnetocaloric Effect
Total Entropy
Magnetic refrigeration
O. Tegus et al. Nature 415 (2002) 150-152
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Introduction Measurement of ∆Tad Results Conclusions
Magnetocaloric Effect
Magnetic Entropy Change
M (T ) and its relation with ∆SM (T )
P. Alvarez-Alonso et al., Phys. Rev. B. 86(2012)184411
Isothermal Magnetic Entropy Change
Maxwell Relation
∆S (T , H) = −∫ H
0
(∂M∂T
)P,H
dH
Refrigerant capacity
P. Gorria et al., J. Phys. D: Appl. Phys. 41 (2008)192003
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Introduction Measurement of ∆Tad Results Conclusions
Magnetocaloric Effect
Adiabatic Temperature Change
Temperature dependence of ∆Tad for Gd Indirect measurement
∆Tad (T , H) = −∫ Hmax
0
TCP,H
(∂M∂T
)P,H
dH
P. Alvarez-Alonso et al. Key Eng. Mater. 644 (2015) 215-218
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Introduction Measurement of ∆Tad Results Conclusions
Measurement system
P. Alvarez-Alonso et al. Key Eng. Mater. 644 (2015) 215-218
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-In bulk alloys
Martensitic Transformation
Ni50Mn35In15
Ni50Mn32Cr2In16
Ni47.5Cu2.5Mn35In15
+Heat treatment (900 ◦C - 1 day )
Specimen Composition MS MF AS AF |∆H|
(at. %) (K) (K) (K) (K) (J/g)
Ni50Mn35 In15 Ni50.1Mn35.3In14.6 303 289 304 316 8.8
Ni50Mn32Cr2In16 Ni49.9Mn32.9Cr2.5In14.7 294 277 290 304 10.7
Ni47.5Cu2.5Mn35In15 Ni48.4Cu2.9Mn35.0In13.7 268 259 272 282 6.9
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-In bulk alloys
Magnetization measurements: Low Magnetic Field
Moderate thermal hysteresis (≈ 12 K )
Specimen T MC (K ) T A
C (K )
Ni50Mn35In15 203 314
Ni50Mn32Cr2In16 214 297
Ni47.5Cu2.5Mn35In15 193 305
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-In bulk alloys
Magnetization measurements: High Magnetic Field
TM = (MS + MF ) /2, TA = (AS + AF ) /2
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-In bulk alloys
MCE: Adiabatic Temperature Change
Martensitic Transformation Magnetic Phase Transition
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-Sn Ribbons
Martensitic Transformation
Ni50-xFexMn40Sn10
(x = 0, 2, 4, 6, 8)
NO Heat treatment
Specimen Composition MS MF AS AF |∆H|
(at. %) (K) (K) (K) (K) (J/g)
Ni50Mn40Sn10 Ni50.3Mn39.7Sn9.9 425 408 423 438 16.5
Ni48Fe2Mn40Sn10 Ni48.5Fe2.2Mn39.5Sn9.8 375 358 377 386 14.4
Ni46Fe4Mn40Sn10 Ni46.6Fe4.0Mn39.4Sn9.9 356 340 356 367 14.0
Ni44Fe6Mn40Sn10 Ni45.2Fe6.3Mn38.6Sn9.9 310 297 309 322 13.2
Ni42Fe8Mn40Sn10 Ni42.6Fe8.1Mn39.6Sn9.7 285 267 286 299 12.9
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-Sn Ribbons
Crystal Estructure and Microstructure
a) Ni50Mn40Sn10 b) Ni48Fe2Mn40Sn10
Austenite: B2
Martensite: 6M-orthorhombic
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-Sn Ribbons
Crystal Structure
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-Sn Ribbons
Magnetization measurements: Low Magnetic Field
Low thermal hysteresis (≈8 K )
Specimen T MC (K ) T A
C (K )
Ni50Mn40Sn10 185 444
Ni48Fe2Mn40Sn10 176 393
Ni46Fe4Mn40Sn10 174 369
Ni44Fe6Mn40Sn10 181 322
Ni42Fe8Mn40Sn10 171 287
T0 = (TM + TA)/2
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-Sn Ribbons
Magnetization measurements: High Magnetic Field
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Introduction Measurement of ∆Tad Results Conclusions
Ni-Mn-Sn Ribbons
MCE: Magnetic Entropy Change
Inverse MCE
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Introduction Measurement of ∆Tad Results Conclusions
Conclusions
Influence of doping elements (Fe, Cr, and Cu) and magnetic field onthe MT and MCE in Ni50Mn35In15 and Ni50Mn40Sn10 metamagneticshape memory alloys.
Small dopping by Cu (Cr) instead Ni (Mn) reduces the critical MTtemperatures of the Ni-Mn-In bulk. Ni substitution by Fe linearlydecreases T A
C and MT temperatures for Ni-Mn-Sn ribbons.
The magnetic field decreases the MT temperatures (up to 40 Kfor 12 T ).
∆SmaxM ≈11 J/kgK under µ0∆H =5 T ; ∆Tad up to −2.7 K for
µ0∆H =1.9 T .
Compositional variation of the MSMA by a small doping is effectiveway to tune the parameters responsible for the MCE in thesematerials.
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