Magnetic behaviour of La₇Ru₃O₁₈

Rhombohedral La₇Ru₃O₁₈ can be considered to be nearly geometrically frustrated due to its close structural similarity to the strongly geometrically frustrated compound La_4.87Ru₂O₁₂. The magnetic ordering of La₇Ru₃O₁₈ was explored using a combination of dc and ac magnetic susceptibility measurements. The magnetic phase diagram shows two different ordering regimes. A low-field magnetic phase occurs at applied fields of 0–3 T and temperatures below 10 K, while a high-field phase is found at fields of 3–5 T and temperatures below 9 K.