Small moment antiferromagnetic ordering in single crystalline La2Ni7

Abstract

Single crystals of La2Ni7 have been grown out of a binary, La-Ni melt. Temperature dependent, zero magnetic field, specific heat, electrical resistivity, and low field magnetization measurements indicate that there is a series of antiferromagnetic phase transitions at T1 = 61.0 \pm 0.2 K, T2 = 56.5 \pm 0.2 K and T3 = 42.2 \pm 0.2 K. The three specific heat anomalies found at these temperatures qualitatively have very small entropy changes associated with them and the anisotropic M(H) data saturate at ~ 0.12 μB/Ni; both observations strongly suggesting the AFM order is associated with very small, itinerant, moments. Anisotropic, H||c and H{\perp}c, ρ(H) and M(H) isotherms as well as constant field, ρ(T) and M(T) sweeps manifest signatures of multiple phase lines and result in H-T phase diagrams that are clearly anisotropic. Analysis of M(T) and M(H) data allow for the identification of the two lower temperature magnetically ordered states as antiferromagnetically ordered, with the moments aligned along the crystallographic c-axis, and the higher temperature, T2 < T < T1, state as having a finite ferromagnetic component. In addition, the metamagnetic transition at low temperatures, for H applied along the crystallographic c-axis (H||c) appears to be a near classic example of a spin-flop transition, resulting in a field stabilized antiferromagnetic state with the moments ordered perpendicular to the c-axis. Although the small moment ordering, and existence of multiple phase transitions in field and temperature, suggesting an energetic proximity of these states, could foretell a degree of pressure sensitivity, our measurements of R(T) for applied pressures up to 2.0 GPa indicate that there is very little pressure dependence of T1, T2 and T3.

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References in corpus (5)

• Ferromagnetic Quantum Critical Point Avoided by the Appearance of Another Magnetic Phase in LaCrGe${}_3$ under Pressure
• Pressure-induced ferromagnetism in the topological semimetal EuCd${}_2$As${}_2$
• Formation of short-range magnetic order and avoided ferromagnetic quantum criticality in pressurized LaCrGe${}_3$
• Quantum tricritical point in the temperature-pressure-magnetic field phase diagram of CeTiGe${}_3$
• Avoided ferromagnetic quantum critical point in pressurized La${}_5$Co${}_2$Ge${}_3$

Cited by in corpus (5)

• Weak itinerant magnetic phases of La2Ni7
• Enhancement of the Curie temperature in single crystalline ferromagnetic LaCrGe${}_3$ by electron irradiation-induced disorder
• Electronic signatures of successive itinerant, magnetic transitions in hexagonal La2Ni7
• Quantum critical point followed by Kondo-like behavior due to Cu substitution in itinerant, antiferromagnet ${\text{La}}_2{\text{(Cu}}_x{\text{Ni}}_{1-x}{)}_7$
• Relationship between polymorphic structures and magnetic properties of La${}_{2-x}{A}_x^{\prime }$Ni${}_7$ compounds ($A$' = Sm, Gd)