Anomalous magnetic properties in LaFe11.5Al1.5. Issue 6 (27th January 2020)

• Record Type: Journal Article
• Authors: Sharma, Sanjay; Ahmad, Faizan; Singh, Ankit; Patel, Akhilesh Kumar; Kumar, Pramod
• Is Part Of: Physical chemistry chemical physics. Volume 22:Issue 6(2020)
• Page Start: 3425
• Page End: 3433
• Publication Date: 2020-01-27
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c9cp06670e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : We report the magnetic relaxation, DC magnetization, heat capacity, and X-ray powder diffraction studies of a melt-spun LaFe11.5 Al1.5 compound executed across a temperature range of 5 to 300 K. Abstract : We report the magnetic relaxation, DC magnetization, heat capacity, and X-ray powder diffraction studies of a melt-spun LaFe11.5 Al1.5 compound executed across a temperature range of 5 to 300 K. We have found three magnetic transitions (at temperatures T 1, T 2, and T ord ) in this compound in the zero-field cooled (ZFC) mode, and two magnetic transitions (at T 2 and T ord ) in the field-cooled cooling/warming (FCC/FCW) mode. The ferromagnetic transition (FM) at temperature T 2 indicating hysteresis alludes to a magnetic transition of the first-order (FOT) at lower temperatures. The magnetization study reveals that meta-stable states exist in the low-temperature antiferromagnetically ordered state. Partially reversible behaviour is also observed in the 120–140 K temperature range. The heat capacity data indicates that the magnetic state of this compound is clearly different from that of spin glasses. The magnetocaloric properties of the compound are determined in the form of the isothermal magnetic entropy change ( S M ) and the adiabatic temperature change (Δ T ad ) and the utmost values of S M and T ad for a field variation of 25 kOe observed were 3.1 J kg −1 K −1 and 1.12 K respectively. The relative cooling power (RCP) is ascertained to be 216 J kg −1 for an enforced field of 25 kOe.