Banca de QUALIFICAÇÃO: PEDRO CAETANO SABINO SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : PEDRO CAETANO SABINO SANTOS
DATE: 11/12/2023
TIME: 14:00
LOCAL: Bloco B Auditório 8o Andar
TITLE:

YbV₆Sn₆, a new quantum material candidate

PAGES: 50
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUBÁREA: Física da Matéria Condensada
SPECIALTY: Estados Eletrônicos
SUMMARY:

Heavy Fermions have been studied extensively as an important part in the physics of strongly correlated electron systems over the last few decades. In this work, we present a study of the recently discovered Heavy Fermion compound YbV₆Sn₆ , and seek to identify indicators of quantum criticality through the application of an external magnetic field and hydrostatic pressure. Single crystals were grown by the self-flux method combined with a pre-synthesis in an arc-melting furnace. X-ray diffraction and Rietveld refinements were used for identifying and checking the structural quality of the grown phase. Measurements of electrical transport and specific heat were performed using a PPMS-II Evercool system. The results of resistivity at low temperatures indicated a non-fermionic liquid state, indicative of the proximity to a quantum critical point. Additionally, deviation from Matthiessen's rule suggests a magnetic influence on the type of scattering of conduction electrons. Specific heat measurements confirmed the heavy fermion state of the material and indicated the presence of a Schottky anomaly associated with the crystal electric field (CEF) present in the samples. Magnetic characterization was performed by M vs T and M vs H curves measured in a SQUID magnetometer. Our results show that the pre-synthesis is essential for growing good quality crystals. The M vs H curves provide signatures of CEF present in the samples. The M vs T curves for H parallel to the ab plane show Currie-Weiss temperatures implying FM interactions with an effective moment expected for Yb3+, whereas for H parallel to the c-axis the curves evidence AFM interactions with a lower effective moment, accompanied by a local maximum at 28 K and a local minimum at 15 K due to the effect of the CEF. We thank the support of GPOMS-UNICAMP, CEM-UFABC, CAPES and FAPESP.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 3066318 - JULIAN ANDRES MUNEVAR CAGIGAS
Membro Titular - Examinador(a) Interno ao Programa - 3944999 - ROMARLY FERNANDES DA COSTA
Membro Titular - Examinador(a) Interno ao Programa - 2605463 - JOSE ANTONIO SOUZA
Membro Suplente - Examinador(a) Externo ao Programa - 1734912 - ROOSEVELT DROPPA JUNIOR