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Deppe, M., N. Caroca-Canales, J. G. Sereni, and C. Geibel. "Evidence for a metamagnetic transition in the heavy Fermion system CeTiGe." In Journal of Physics: Conference Series, 012026. Vol. 200. International Conference on Magnetism, ICM 2009 200, no. SECTION 1. Karlsruhe, 2010. Abstract: A recent study of CeTiGe identified this compound as a paramagnetic heavy Fermion system where the full J = 5/2 multiplet is involved in the formation of the ground state. Here we present a preliminary investigation of the dc-magnetization M_dc(H) and of the magnetoresistance Ï(H) of polycrystalline CeTiGe samples in applied magnetic fields up to Î¼₀H = 14 T. The results reveal a pronounced metamagnetic transition at a critical field Î¼₀H_c â‰ˆ 13.5 T at low temperatures, with a step like increase in M_dc(H) of at least 0.6 Î¼_B/Ce. The metamagnetic transition leads to a strong decrease in Ï(H). A clear hysteresis in M_dc(H) and Ï(H) indicate that in CeTiGe these metamagnetic features correspond to a true thermodynamic, first order type transition in contrast to the critical behavior observed in the canonical system CeRu₂Si₂. Measurements at higher temperatures showed a continuous suppression of the metamagnetic transition with increasing T, which vanishes at T âˆ¼ 30 K. Â© 2010 IOP Publishing Ltd. Keywords: Applied magnetic fields; Canonical systems; Continuous suppression; Critical behavior; Critical fields; DC magnetization; First order; Heavy fermion systems; Higher temperatures; Low temperatures; Metamagnetic; Metamagnetic transitions; Polycrystalline; Cerium; Cerium compounds; Electric resistance; Magnetic field effects; Magnetoresistance; Magnetism http://fisica.cab.cnea.gov.ar/bt/refbase/show.php?record=599
Encina, S., P. Pedrazzini, J. G. Sereni, and C. Geibel. "Low temperature thermopower and magnetoresistance of Sc-rich CeSc1-xTixGe." Physica B: Condensed Matter 536 (2018): 133–136. Abstract: In CeSc1-xTixGe, Ti-alloying reduces the record-high antiferromagnetic (AFM) ordering temperature found in CeScGe at TN=46K and induces ferromagnetism for xâ‰¥0.5. In this work we focus on the AFM side, i.e. Sc-rich samples, and study their thermopower S(T) and magnetoresistance Ï(H,T). The measured S(T) is small in comparison with the thermopower of other Ce-systems and shows some features that are compatible with a weak hybridization between the 4f and band states. This is a further hint pointing to the local character of magnetism in this alloy. Magnetic fields up to 16T have a minor effect on the electrical resistivity of stoichiometric CeScGe. On the other hand, for x=0.65, we find that fields above 4T suppress the hump in Ï(T). Furthermore, the 4.2K magnetoresistance displays a strong decrease in the same field range, also in coincidence with magnetization results from the literature. Our results indicate that Ï(T,H) is a proper tool to assess the Hâˆ’T phase diagram of this system. Keywords: CeScGe; CeTiGe; Antiferromagnetism; Transport properties; Low temperatures; Magnetic field http://fisica.cab.cnea.gov.ar/bt/refbase/show.php?record=765

Abstract: A recent study of CeTiGe identified this compound as a paramagnetic heavy Fermion system where the full J = 5/2 multiplet is involved in the formation of the ground state. Here we present a preliminary investigation of the dc-magnetization M_dc(H) and of the magnetoresistance Ï(H) of polycrystalline CeTiGe samples in applied magnetic fields up to Î¼₀H = 14 T. The results reveal a pronounced metamagnetic transition at a critical field Î¼₀H_c â‰ˆ 13.5 T at low temperatures, with a step like increase in M_dc(H) of at least 0.6 Î¼_B/Ce. The metamagnetic transition leads to a strong decrease in Ï(H). A clear hysteresis in M_dc(H) and Ï(H) indicate that in CeTiGe these metamagnetic features correspond to a true thermodynamic, first order type transition in contrast to the critical behavior observed in the canonical system CeRu₂Si₂. Measurements at higher temperatures showed a continuous suppression of the metamagnetic transition with increasing T, which vanishes at T âˆ¼ 30 K. Â© 2010 IOP Publishing Ltd.

Keywords: Applied magnetic fields; Canonical systems; Continuous suppression; Critical behavior; Critical fields; DC magnetization; First order; Heavy fermion systems; Higher temperatures; Low temperatures; Metamagnetic; Metamagnetic transitions; Polycrystalline; Cerium; Cerium compounds; Electric resistance; Magnetic field effects; Magnetoresistance; Magnetism

http://fisica.cab.cnea.gov.ar/bt/refbase/show.php?record=599

Abstract: In CeSc1-xTixGe, Ti-alloying reduces the record-high antiferromagnetic (AFM) ordering temperature found in CeScGe at TN=46K and induces ferromagnetism for xâ‰¥0.5. In this work we focus on the AFM side, i.e. Sc-rich samples, and study their thermopower S(T) and magnetoresistance Ï(H,T). The measured S(T) is small in comparison with the thermopower of other Ce-systems and shows some features that are compatible with a weak hybridization between the 4f and band states. This is a further hint pointing to the local character of magnetism in this alloy. Magnetic fields up to 16T have a minor effect on the electrical resistivity of stoichiometric CeScGe. On the other hand, for x=0.65, we find that fields above 4T suppress the hump in Ï(T). Furthermore, the 4.2K magnetoresistance displays a strong decrease in the same field range, also in coincidence with magnetization results from the literature. Our results indicate that Ï(T,H) is a proper tool to assess the Hâˆ’T phase diagram of this system.