Chemical disorder driven reentrant spin cluster glass state formation and associated magnetocaloric properties of Nd2Ni0.94Si2.94. Issue 10 (26th February 2018)

• Record Type: Journal Article
• Authors: Pakhira, Santanu; Mazumdar, Chandan; Ranganathan, R.; Giri, S.
• Is Part Of: Physical chemistry chemical physics. Volume 20:Issue 10(2018)
• Page Start: 7082
• Page End: 7092
• Publication Date: 2018-02-26
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c7cp08574e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : We report the synthesis of a new ternary intermetallic compound Nd2 Ni0.94 Si2.94 that exhibits large magnetocaloric effect in the presence of reentrant spin cluster state formation. Abstract : In this work, we report the synthesis of a new ternary intermetallic compound, Nd2 Ni0.94 Si2.94, that forms in single phase only in a defect crystal structure. The compound exhibits an antiferromagnetic transition below 7.2 K ( T N ) followed by a spin cluster freezing behaviour below 2.85 K ( T f ), which makes the compound a reentrant spin cluster glass system. The detailed studies of dc and ac magnetization, heat capacity, non-equilibrium dynamical behaviour, viz., aging effect, temperature and field dependent magnetic relaxation and magnetic memory effect establish the compound to be a cluster-glass material below freezing temperature. The interplay between competing exchange coupling ( c / a ≃ 1.04 ⇒ J NN ≃ J NNN ) and chemical disorder driven variation in the electronic environment among the Nd ions has been argued to be responsible for such a metastable state formation. A considerable value of MCE parameters (−Δ S maxM ∼ 11.4 J kg −1 K −1, RCP ∼ 160 J kg −1 and Δ T ad ∼ 5.2 K for a field change of 70 kOe) is obtained for this magnetically frustrated glassy compound.