Quantum criticality in NdFe2Ga8 under magnetic field

Single-crystal growth and magnetic anisotropy in PrFe2Ga8

“…55) [22]. Our SCXRD analysis of PrFe 2 Ga 8 confirms that PrFe 2 Ga 8 crystallizes in the CaCo 2 Al 8 orthorhombic structure, which is also adopted by similar compounds such as NdFe 2 Ga 8 [26], CeCo 2 Ga 8 [32], and CeFe 2 Al 8 [28]. The refined lattice parameters are a = 12.4612(6) Å, b = 14.3628(9) Å and c = 4.0580(2) Å, respectively.…”

“…Heavy-fermion compounds LnM 2 X 8 (Ln = La, Ce, Pr, or Nd; M = Co, Fe, or Rh; X = Al, Ga, or In) [22][23][24][25][26][27][28][29][30][31][32][33] can be classified as the quasi-one-dimensional systems because the Ln-Ln bond is much shorter along the c-axis than those in the ab-plane. They show complex magnetic orders [22][23][24][25][26][27][28]30], Kondo lattice states [31][32][33], or quantum critical points (QCPs) [26,32,33]. In NdFe 2 Ga 8 , a QCP behavior of the three-dimensional spin-density-wave type occurs after the suppression of magnetic order when applied magnetic fields are parallel to the c-axis (H // c).…”

“…In NdFe 2 Ga 8 , a QCP behavior of the three-dimensional spin-density-wave type occurs after the suppression of magnetic order when applied magnetic fields are parallel to the c-axis (H // c). However, there is no indication of QCP when applied magnetic fields are perpendicular to the c-axis (H ⊥ c) [26], indicating an anisotropic behavior. Though studies of polycrystalline PrFe 2 Ga 8 found that PrFe 2 Ga 8 is antiferromagnetically ordered at 17 K [22], its magnetic anisotropy was not investigated.…”

An emerging global picture of heavy fermion physics

“…Motivated by the studies of nematicity in pnictides, we have recently discovered an in-plane anisotropic response to the uniaxial pressure without necessarily breaking the rotational lattice symmetry in the hidden order state of URu 2 Si 2 [171]. In the newly-synthesized single crystal NdFe 2 Ga 8 , a 'hidden order' transition was also observed, possibly associated with some yet-to-beidentified multipolar order [172,173]. Electric quadrupole orders have been observed in Pr-based heavy fermion compounds such as PrOs 4 Sb 12 with non-Kramers doublet for the crystal field ground state of Pr 3+ , which may be responsible for their unusual superconductivity or other exotic properties [174,175].…”

Strong magnetic anisotropy in PrRu2Ga8 and PrCo2Al8 single crystals

“…The so-called 128-family with a general formula of LnT 2 X 8 (Ln = La-Nd, Sm, Eu, Yb, and Sr; T = Fe, Co, Ru, Rh, and Ir; X = Al, Ga, and In) [17] shows diverse properties including non-fermi liquid behavior in CeCo 2 Ga 8 [18], a quantum critical point in NdFe 2 Ga 8 [19], magnetic orders in PrFe 2 Al 8 [20] and EuIr 2 In 8 [21]. For Pr-based 128-family compounds, Pr 3+ ions have a lattice site symmetry of monoclinic m (Cs) [22].…”