Low-Temperature Heat Capacity Measurements in LaNiGa₂

LaNiGa₂ is a centrosymmetric superconductor with orthorhombic crystal structure. Previous NMR measurements indicate that it breaks time-reversal symmetry due to the onset of spontaneous magnetic fields as it transitions into the superconducting phase, implying the possibility of spin-triplet pairing states. However, previous London penetration depth measurements agree with isotropic s-wave behavior down to 50 mK. One hint of non-BCS behavior comes from specific heat. Fits to a BCS form are successful over limited temperature ranges, but not over the entire range from 300 mK to Tc. We further investigate this discrepancy by using a dilution refrigerator to extend specific heat data to lower temperatures.