First-order nature of the ferromagnetism in CeIn<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow /><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>investigated using muon spin rotation and by systematic substitution of La for Ce
Physical review. B, Condensed matter and materials physics