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Updated: Mar 24, 2026
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Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.7K
Valence fluctuation and magnetic ordering in EuNi2(P(1-x)Ge(x))2 single crystals
U B Paramanik1, A Bar, Debarchan Das
1Department of Physics, Indian Institute of Technology, Kanpur 208016, India.
Summary
Germanium substitution in EuNi2P2 tunes its magnetic properties, stabilizing an antiferromagnetic state and revealing valence fluctuations. This research explores the magnetic-nonmagnetic boundary in rare-earth compounds.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Magnetism
Background:
- Europium (Eu) based compounds exhibit unusual phases and phase transitions near magnetic-nonmagnetic boundaries.
- EuNi2P2 is a unique valence-fluctuating Eu system where Eu valence remains near 2.5 at low temperatures.
- Ge substitution offers a method to tune the valence and magnetic properties of EuNi2P2.
Purpose of the Study:
- To investigate the impact of Germanium (Ge) substitution on the magnetic, thermodynamic, and transport properties of EuNi2(P(1-x)Ge(x))2 single crystals.
- To understand the evolution of magnetic ordering and valence state with increasing Ge concentration.
- To explore the interplay between valence fluctuations, Kondo effect, and magnetic ordering.
Main Methods:
- Growth of EuNi2(P(1-x)Ge(x))2 single crystals for 0.0 ≤ x ≤ 0.5.
- Experimental studies including magnetic, thermodynamic (specific heat), and transport property measurements.
- Electronic structure calculations to determine Eu valence states.
Main Results:
- Increasing Ge doping (x > 0.4) leads to a stable antiferromagnetic (AFM) ordered state with a Néel temperature (T(N)) of 12 K for x = 0.5.
- Reduced magnetic entropy at T(N) for x = 0.5 suggests the presence of valence fluctuation or Kondo effect.
- An enhanced Sommerfeld coefficient in specific heat measurements indicates changes in electronic behavior upon Ge doping.
Conclusions:
- Ge substitution effectively tunes the magnetic properties of EuNi2P2, stabilizing an AFM state.
- Electronic structure calculations confirm a non-integral valence in EuNi2P2 and a stable divalent Eu state in EuNi2Ge2.
- The study provides insights into the complex interplay of valence fluctuations and magnetic ordering at the magnetic-nonmagnetic boundary.
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