title: Enhanced electrical resistance at the field-induced magnetic transitions in some non-stoichiometric and stoichiometric Tb-based ternary germanides.
abstract: We present the magnetic and transport behavior of some Tb compounds, namely TbIrGe(2), TbFe(0.4)Ge(2) and TbCo(0.4)Ge(2). The stoichiometric germanide TbIrGe(2) exhibits at least two distinct magnetic transitions in a close temperature interval around 10 K. Non-stoichiometric compounds, TbFe(0.4)Ge(2) and TbCo(0.4)Ge(2), undergo magnetic ordering around 17 and 19 K, respectively. The magnetic state of these compounds appears to be antiferromagnetic-like. Qualitatively there is a correlation between the field response of the magnetization (M), the magnetoresistance (MR) and the entropy change (ΔS) curve in all three compounds. That is, these Tb compounds exhibit a positive MR and ΔS beyond a magnetic field where M also shows a field-induced transition. On the basis of this correlation, we conclude that magnetic disorder/fluctuations beyond a critical field-a phenomenon called 'inverse metamagnetism'-rather than metamagnetism is induced in these compounds.
authors.affiliation: Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India. kmukherjee@.tifr.res.in
authors.forename: K
authors.initials: K
authors.lastname: Mukherjee
authors.forename: Kartik K
authors.initials: KK
authors.lastname: Iyer
authors.forename: E V
authors.initials: EV
authors.lastname: Sampathkumaran