Unusual bidirectional frequency dependence of dynamical susceptibility in hexagonal intermetallic Pr2Ni0.95Si2.95

• Published in: Scientific reports Vol. 8; no. 1; pp. 1 - 15
• Main Authors: Pakhira, Santanu, Mazumdar, Chandan, Basu, Abhik, Ranganathan, R., Bhowmik, R. N., Satpati, Biswarup
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05-10-2018; Nature Publishing Group
• Subjects: 639/301/119/997; 639/766/119/997; Aging; Freezing; Frequency dependence; Humanities and Social Sciences; Intermetallic compounds; multidisciplinary; Scaling; Science; Science (multidisciplinary); Temperature effects; Short Range Magnetic Correlations; Magnetic Relaxation Behavior; Opposite Frequency Shifts; Magnetic Memory Effect; Spin Freezing Temperature
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-32740-4

In this study, the synthesis of a novel ternary intermetallic compound Pr
2
Ni
0.95
Si
2.95
forming in single phase only by deliberately introducing vacancies in Ni/Si site is reported. The detailed studies on dc magnetization, heat capacity, ac magnetization & associated dynamical scaling, different types of non-equilibrium dynamical behaviour,
viz
., magnetic relaxation behaviour as a function of wait time and temperature, aging phenomena, and magnetic memory effect firmly establish that the compound exhibits spin freezing behaviour below 3.3 K (T
f
). However, below T
f
, temperature dependence of ac susceptibility data exhibit an additional peak that shows reverse frequency dependence to that generally observed in a glassy system. The unusual bidirectional frequency dependence in a single magnetic system is of significant interest and rarely reported in literature. Competing exchange interaction arising from
c
/
a
 ~ 1 and crystallographic randomness driven magnetic phase separation has been argued to be responsible for such observation. The reverse frequency shift of the low temperature peak has been described on the basis of a simple phenomenological model proposed in this work.