Pressure Dependent Magnetism in Y1.05(Mn0.95Al0.05)2

The Laves phase compound YMn2 exhibits a discontinuous transition from a spin fluctuating Pauli paramagnetic state above 110 K to an expanded, localised moment helical antiferromagnetic state below 110 K. Substitution of Al for Mn in the pseudo-binary compound Y(Mn1-xAlx)2 exerts a negative chemical pressure, expanding the unit cell and further localizing the Mn moment. Here we present the results of a μSR study of spin fluctuations in Y(Mn1-xAlx)2 (x = 0.05) in which external mechanical pressure (4.5 kbar) is applied to counteract the Al induced chemical pressure and destabilize the local Mn moment.