Anisotropic magnetic excitations and incipient Neel order in Ba(Fe1-xMnx)(2)As-2

Autor(es)

Garcia, Fernando A. ; Ivashko, Oleh ; McNally, Daniel E. ; Das, Lakshmi ; Piva, Mario M. ; Adriano, C. ; Pagliuso, Pascoal G. ; Chang, Johan ; Schmitt, Thorsten ; Monney, Claude

• Tipo de documento: Artigo Científico
• Fonte: PHYSICAL REVIEW B; v. 99, n. 11, p. 7-pg., 2019-03-14.

Resumo

It is currently understood that high temperature superconductivity (SC) in the transition metal (M) substituted iron arsenides Ba(Fe1-xMx)(2)As-2 is promoted by magnetic excitations with wave vectors (pi, 0) or (0, pi). It is known that while a small amount of Co substitution lead to SC, the same does not occur for Mn for any value of x. In this work, magnetic excitations in the iron arsenides Ba(Fe1-xMnx)(2)As-2 (x = 0.0, 0.007, 0.009, 0.08) are investigated by means of resonant inelastic x-ray scattering (RIXS) at the Fe L-3 edge, for momentum transfer q along the high symmetry Brillouin zone (pi, 0) and (pi, pi) directions. It is shown that with increasing Mn content (x), the excitations become anisotropic both in dispersion and lineshape. Both effects are detected even for small values of x, evidencing a cooperative phenomenon between the Mn impurities, that we ascribe to emerging Neel order of the Mn spins. Moreover, for x = 0.08, the excitations along q parallel to (pi, 0) are strongly damped and nearly nondispersive. This result suggests that phases of arsenides containing local moments at the FeAs layers, as in Mn or Cr substituted phases, do not support high temperature SC due to the absence of the appropriate magnetic excitations. (AU)

• Processo FAPESP: 15/15665-3 - Estudos dos efeitos de diferenciação orbital das propriedades magnéticas e supercondutoras de compostos à base de FeAs
• Beneficiário: Mário Moda Piva
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 17/10581-1 - Fenômenos emergentes em sistemas de dimensões reduzidas
• Beneficiário: Pascoal Jose Giglio Pagliuso
• Modalidade de apoio: Auxílio à Pesquisa - Projetos Especiais
• Processo FAPESP: 17/25269-3 - Estudos em altas pressões dos compostos SrFe2As2, CeAuBi2 e CaMn2Bi2
• Beneficiário: Mário Moda Piva
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto