TY - JOUR
T1 - Magnetic clusters on the verge of long range ferromagnetism in Lu(Fe0.75Al0.25)2and Lu(Fe0.50Al0.50)2alloys
AU - Piquer, C.
AU - Fernández Barquín, L.
AU - Chaboy, J.
AU - Alba-Venero, D.
AU - Laguna-Marco, M. A.
AU - Boada, R.
AU - Sánchez-Marcos, J.
AU - Puente-Orench, I.
N1 - Funding Information:
This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) grants MAT2011-27573-C04 , MAT2010-16022 , MAT2014-54425-R and MAT2014-55049-C2-R , and by the Aragón DGA NETOSHIMA grant. MAL-M acknowledges CSIC and the European Social Fund for postdoctoral contract. Institut Laue-Langevin (Grenoble) is acknowledged for allocating beam time.
Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2017
Y1 - 2017
N2 - Lu(Fe0.75Al0.25)2and Lu(Fe0.50Al0.50)2alloys have been produced by arc-melting. DC and AC magnetization, Mössbauer spectroscopy, specific heat and neutron diffraction experiments have been performed to determine their magnetic ground state. DC magnetization curves measured at low fields (H < 1 kOe) evidence two peaks, at TSROand Tf, and magnetic irreversibility. The peak at TSROvanishes and the one at Tfsmears out when high fields (H ≥ 1 kOe) are applied. The thermal variation of AC susceptibility shows that both transitions at TSROand Tfare frequency dependent. Neither magnetic splitting nor broadening is observed in the Mössbauer spectra of both compounds in the Tf< T < TSROthermal range. A magnetically split spectrum is only observed in Lu(Fe0.75Al0.25)2for T < Tf.The absence of long range ferromagnetic order in both alloys is confirmed by specific heat and neutron diffraction measurements. The overall interpretation points to a clustered magnetic environment due to the random positions of Fe atoms in the crystallographic cell. At TSROa short range ferromagnetic order takes place within the clusters, which become frustrated at Tf, when the random anisotropy of the clusters enables their freezing.
AB - Lu(Fe0.75Al0.25)2and Lu(Fe0.50Al0.50)2alloys have been produced by arc-melting. DC and AC magnetization, Mössbauer spectroscopy, specific heat and neutron diffraction experiments have been performed to determine their magnetic ground state. DC magnetization curves measured at low fields (H < 1 kOe) evidence two peaks, at TSROand Tf, and magnetic irreversibility. The peak at TSROvanishes and the one at Tfsmears out when high fields (H ≥ 1 kOe) are applied. The thermal variation of AC susceptibility shows that both transitions at TSROand Tfare frequency dependent. Neither magnetic splitting nor broadening is observed in the Mössbauer spectra of both compounds in the Tf< T < TSROthermal range. A magnetically split spectrum is only observed in Lu(Fe0.75Al0.25)2for T < Tf.The absence of long range ferromagnetic order in both alloys is confirmed by specific heat and neutron diffraction measurements. The overall interpretation points to a clustered magnetic environment due to the random positions of Fe atoms in the crystallographic cell. At TSROa short range ferromagnetic order takes place within the clusters, which become frustrated at Tf, when the random anisotropy of the clusters enables their freezing.
KW - Cluster spin-glass behavior
KW - Intermetallic compounds
KW - Laves phases
KW - Magnetic measurements
KW - Mössbauer spectroscopy
KW - Short-range ferromagnetic order
UR - http://www.scopus.com/inward/record.url?scp=85000444299&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2016.10.181
DO - 10.1016/j.jallcom.2016.10.181
M3 - Article
AN - SCOPUS:85000444299
SN - 0925-8388
VL - 695
SP - 704
EP - 714
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
ER -