镍

Left metal radical, the simplified left-side form of 金. Carries the meaning: 镍 is the chemical element nickel, one of dozens of modern element names coined by adding the metal radical to a phonetic body. Same pattern as 铜 copper, 铁 iron, 铝 aluminium, 钠 sodium.

Right 臬 supplies the sound niè directly. Originally 臬 meant a measuring post or target arrow used as a standard, but in 镍 it functions purely as a phonetic frame. Modern Chinese element names are designed this way - a phonetic chosen to match the foreign sound (nickel → niè), plus the radical naming the category (metal).