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The sharp onset of order and jump in heat capacity imply a first order phase transition at T$_{Q}$ ≈ 0 . 13 . Treating this nematic order at the level of a Ginzburg- 

Landau theory, the free-energy terms allowed by lattice and spin rotational symmetries are 

where Q 2 is defined in Eq. (18), the third order invariant Q 3 

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is given by 

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In a three–dimensional uniaxial nematic state, such as that 

